BY JEFFREY A. HARWELL
Large-loss fires involving fully sprinklered buildings are extremely rare these days. Consequently, when the large-loss fire described below occurred in February 2011 at a warehouse with high piled storage in the Regency I Warehouse in Grand Prairie, Texas, the nation’s interest was piqued. What especially caused the fire service and related industries to ask what went wrong was the fact that this warehouse had been equipped with an Early Suppression Fast Response (ESFR) sprinkler system. At the time, this fire was thought to be the first large-loss fire involving the new ESFR technology.
THE BUILDING
A building permit for the Regency I Warehouse was obtained in early 1995, and construction was started during that summer. The 405,780-square-foot speculative warehouse was in the far northwest corner of Grand Prairie along the Arlington border. The structure measured approximately 800 × 500 feet and featured tile-wall construction with a system of steel columns, bar joists, and beams supporting a rubber membrane roof on a metal deck. The roof was 30 feet above the finished floor along the east and west exterior walls and rose to a height of 36 feet above the finished floor at the center of the building. The roof included four- × eight-foot skylights scattered throughout the warehouse area. Situated along the south end of the building was 5,000 square feet of office space. There were a few isolated offices within the warehouse space. A fire lane completely encircled the building.
During construction, five fire hydrants, fed from a 12-inch circulating water main, were added on site. An eight-inch underground water line for the sprinkler system came off a looped main on the east side of the building, entered the fire pump room, and supplied a 1,500-gallon-per-minute (gpm) diesel fire pump. From there, the supply piping went back underground and teed off to the north and south. The underground supply piping entered the warehouse at six locations along the east wall. All sprinkler risers were along the east wall where the underground supply piping entered the building. A fire department connection (FDC) was along the fire lane on the east side of the building; four-inch piping extended from the FDC into the fire pump room.
SPRINKLER BACKGROUND
When the building was first constructed, the warehouse featured an ESFR sprinkler system that consisted of 10 sprinkler system zones. The ESFR sprinkler technology was developed during the mid-1980s. The ESFR system has been considered revolutionary because it is the first sprinkler system developed to extinguish the fire as opposed to controlling it. As the name indicates, this is accomplished through fast-response sprinklers that operate at a high discharge pressure flowing large amounts of water. For this reason, most ESFR systems feature a fire pump. This warehouse was no different. Another key factor is that the water droplets from the sprinkler are larger, enabling the water to reach deeper into the storage pile.
Owners like the ESFR systems because they can normally delete troublesome in-rack sprinklers and still store a wide variety of materials. Firefighters like the systems because the fire is usually extinguished prior to their arrival, meaning they don’t have to formulate an attack plan that involves putting out a fire that could be 30 feet off the ground.
VARIANCE REQUESTS
During the design phase of the project, two variances involving fire and life safety issues were requested. The first request involved eliminating all ceiling-mounted smoke and heat vents and providing a mechanical smoke exhaust system in their place. The request also asked for a reduction in the capacity of smoke exhaust fans to be provided. The request was based on an engineering report that determined these changes were justified based on the quick extinguishment and limited smoke production from any fire involving an ESFR system. Instead of the 10 air changes per hour required by code, the 23 fans would provide three air changes per hour. Manual start switches for the fans were provided in the fire pump room.
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| (1) The truck sets up to operate on the southeast side of the building. The fire pump room is at the far right. (Photos by author.) |
The same engineering report asked for the elimination of smoke curtains. Once again, the request was based on the limited fire size and smoke production from a fire protected by an ESFR system. Both variances were approved.
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| (2) This photo was taken on the east side of the building at the north end of the warehouse. The initial attacks on the fire were made through these doors. In fact, the three handlines can still be seen in the bay door just to the right of the dumpster (one three inch and two 1¾ inch). |
The other variance request involved increased travel distance from the middle of the warehouse to an exit. The building code allowed a maximum travel distance of 200 feet, and the owner wished to extend this to 300 feet. Once again, the justification for this request was the expected fast response and rapid extinguishment provided by the ESFR sprinkler system. Calculations were presented showing the time it would take for the smoke layer to descend from the roof and overtake a fleeing occupant. These calculations showed the smoke layer would not descend far enough to endanger fleeing occupants based on the anticipated operation of the ESFR system. This variance was approved during a Board of Appeals meeting.
OCCUPANCY/SPRINKLER CHANGES
Soon after the initial sprinkler system installation was complete, a new tenant leased the eastern half of the building. Based on requirements from the city and the tenant’s insurance carrier, changes had to be made to the existing ESFR sprinkler system. The tenant stored carpet rolls on double-row racks up to 20 feet high on mostly solid shelving. The tenant was required to change out all ESFR heads and replace them with extra large orifice heads. In-rack automatic sprinklers were also added. The extra large orifice heads were specified because of the stubborn nature of fires involving carpet rolls and the anticipation that manual firefighting efforts would be necessary for final extinguishment. The changes involved Sprinkler Systems 2, 4, 6, 8, and 10.
At the time of the fire, a distribution company had replaced the carpet company as the occupant of the eastern half of the building as well as a small portion of the northwest corner. A mail-processing and storage company occupied the remainder of the western half of the building. According to records, there were no additional modifications to the sprinkler system based on these two tenants occupying the building, although the in-rack sprinklers had to be removed when the racks associated with the carpet storage were removed. There is no record that a new maximum storage height was established.
The new sprinkler system design for the carpet storage area was .3 gpm per square foot over the most remote 2,000 square feet for a system demand of 1,917 gpm at 8 psi at the city main and 1,668 gpm at 72.1 psi at the bottom of the riser.
Based on fire investigators’ interviews with employees of the distribution company after the fire, the storage method in the area of the fire consisted of palletized storage on plastic pallets with no racks. Each pallet consisted of 8,153 empty soda cans (with no lids) and was reported to be seven to eight feet in height. A Class A plastic slip sheet was situated between each row of cans; a slip sheet covered the top of the cans with an unknown number of bands around the pile. There was no plastic on the sides of each pallet load. According to the employees, pallets were stored three high on the floor with a maximum height of 20 to 24 feet. The height from the floor to the bottom of the steel bar-joist roof assembly ranged from 27 to 33 feet. The fire department’s later investigation revealed the actual storage height was generally more than 27 feet.
FIRE ALARMS
It was believed that there were three fire alarm systems. The distribution company had an addressable system, which meant every fire alarm device in the building had a unique identifying address and firefighters could more easily pinpoint which device was causing the alarm.
The mail-processing company had a nonaddressable hard wired system, which meant multiple devices might be on the same initiating zone. Thus, arriving firefighters could have a message at the panel stating “Zone 5 Southeast Warehouse Duct Smokes,” and firefighters would have to figure out which one of the duct detectors was actually in alarm.
There was likely an unknown type of system in the fire pump room to monitor the devices in that room. It’s believed these panels were interconnected, which meant if one panel went into alarm, it would then trigger the other two panels to go into alarm.
LOCATING THE FIRE
At 7:39 p.m. on February 7, 2011, the Grand Prairie 911 office received a call from an alarm company advising that it had received a burglar alarm from the business at 1029 Post & Paddock Road. When the alarm company reached someone on site, the occupant reported the northeast end of the building was filling with smoke. A first-alarm assignment consisting of Engines 8, 4, and 1; Truck 8; Air 1; and Battalion 1 was dispatched to the address. On this particular night, most engine crews were operating with three firefighters; truck companies had four firefighters.
| Figure 1 |
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Seven minutes later, Engine and Truck 8 arrived at the front of the building (south side) with the captain of Truck 8 assuming command of the fire. Engine 8 checked with an employee at the front of the building, who said that the fire was in Suite 1029 at the northwest corner of the building. Engine 8 then drove down to this location. While water supply was being established, a crew entered the building to assess the situation. When crews entered the space, they encountered light smoke conditions but no signs of fire. Engine 4 arrived at this time and was directed to assist Truck 8’s crew with laddering the building in the area of the reported fire.
A short while later, reports were received that the smoke was heavier on the northeast corner; all companies were ordered to relocate to this portion of the building. Since initial companies were having a difficult time locating the seat of the fire, command ordered a second alarm to be transmitted at 7:55 p.m. This alarm consisted of Engine 3, Truck 1, and Ambulance 74. At this point, Battalion 1 arrived on scene and assumed command.
Engine 4 was the first unit to arrive on the northeast corner; its crew entered the building to attempt to locate the fire origin while the apparatus operator established a new water supply. The crew entered the warehouse through an open personnel door in the vicinity of the fire pump room and observed light smoke conditions. As they moved northward, the smoke became heavier. They began opening rollup doors as they encountered them. When they neared the north exterior wall, they turned west and soon observed soda cans floating in a large pool of water that had collected on the floor. When they turned off their flashlight, they were able to see flames in and around the top of the pallet stacks of soda cans at ceiling level—approximately 30 feet off the floor. Later investigation revealed the location of the fire was approximately 75 feet from the north exterior wall and 210 feet from the east exterior wall.
FIRST INTERIOR ATTACK
At 7:57 p.m., the third-due engine on the first-alarm assignment (Engine 1) was directed to find and supply the sprinkler system FDC. The remainder of Engine 1’s crew became the rapid intervention company (RIC). At 8:13 p.m., Engine 1’s apparatus operator notified command that the connection was now being supplied. During this period, Truck 8 was directed to start positive pressure ventilation (PPV). At 8:05 p.m., confusion arose as to which companies were in the building and whether they were accounted for. Command ordered all companies to exit the building and regroup.
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| (3) Note the massive piles of empty soda cans that accumulated in the warehouse once the piles became unstable. This photo was taken in the northeast portion of the warehouse, near the area of origin. The sprinkler manifold for Systems 5 and 10 is visible in the center of the photo. |
At 8:17 p.m., crews from Engines 4 and 8 and Truck 1 entered the building to attack the fire with two 1¾-inch handlines supplied by Engine 4. One line had been extended to 300 feet, and the other line to 400 feet. When members arrived in the area of the fire, more cans had collapsed. Because of near-zero visibility, a thermal imaging camera (TIC) had to be placed in front of the nozzleman in an attempt to get water directed toward the fire, which was still confined to the top of the palletized storage at ceiling level. Companies operated from this position until their air supplies were exhausted, at which time they exited the building for new air bottles. During this attack, the fire intensity did not decrease.
A conference was held, and it was decided to move Truck 1’s 100-foot rear-mounted ladder adjacent to the bay door closest to the fire and extend the prepiped aerial nozzle into the top of the bay door. Firefighters hoped the greater volume of the master stream would quickly knock down the fire. It was now 8:50 p.m., an hour and 10 minutes into the incident. After operating for a short time, firefighters determined water was not reaching the fire, and Truck 1’s master stream was shut down.
SECOND AND THIRD INTERIOR ATTACKS
Crews then mounted a second interior attack at 9:00 p.m. by stretching two additional handlines (one three-inch and one 1¾-inch) off Truck 1 (operating as a quint) to supplement the two original attack lines. Instead of setting up at the previous location, crews were forced to move farther east because of the massive piles of collapsed soda cans that had accumulated since they left. These handlines were operated until companies had to exit for new air bottles. Conditions in the interior had not changed—heavy white smoke with near-zero visibility but no heat.
| Figure 2 |
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At 9:31 p.m., command requested a third alarm, which brought four mutual-aid Arlington (TX) Fire Department (AFD) units consisting of Engine 5, Engine 2, Quint 1, and Battalion 1. On arrival, Arlington Quint 1 was teamed up with Truck 8 to initiate vertical ventilation by taking out skylights in the area of the fire. Crews performing this task confirmed with command that they could hear sprinklers operating below them. At this time, power was restored to the east side of the warehouse in an attempt to get the smoke exhaust fans started. Units on scene could not confirm if the fans were operating, and attempts to turn on the fans manually did not produce any notable changes.
At 10:34 p.m., crews initiated a third attack on the fire. Nine minutes later, firefighters were inundated with a wave of collapsing soda cans, and two firefighters became trapped under the hundreds of fallen soda cans. Although both firefighters were freed, one had been struck by a falling pallet and did not return to active service. At this point, the handlines had to be abandoned under the massive debris as crews exited the building.
Because of the danger involved with positioning firefighters in the immediate vicinity of the fire, command placed a mutual-aid request with Dallas/Fort Worth International Airport at 10:50 p.m. for its large truck-mounted fan to respond to the scene. Without ventilation, firefighters were having an extremely difficult time in determining what they were up against and the best way to attack it.
FOURTH INTERIOR ATTACK
As the fan truck was arriving, an AFD unit advised it had opened doors on the north side of the building and observed heavy fire approximately 50 feet inside the door. Orders were given at 11:20 p.m. to hold up on using the fan truck while companies mounted a fourth interior attack from the north side of the building. All previous attacks had been made from the east side. When units on the north side reported they had knocked down all visible fire, firefighters thought they might have the upper hand. Orders were given to close all overhead doors in preparation for using the large truck-mounted fan for what firefighters hoped would be the overhaul process.
As the last doors were being closed, an AFD unit advised it had located more fire inside another door on the north side. Command contemplated mounting another interior attack. But, after chasing the fire all night with zero visibility and additional firefighter injuries a distinct possibility, command elected to go ahead and use the truck-mounted fan in an attempt to improve overall operating conditions.
DETERIORATING CONDITIONS
At 11:43 p.m., a fourth alarm was requested for additional personnel. This brought Irving Engine 5 and Dallas Engine 26 and a battalion chief from each department to the fireground. The truck-mounted fan operated for a little over an hour and never proved effective for improving conditions. At 1:17 a.m., another interior attack was being considered, but when fire vented through one of the skylights, command made sure all personnel were out of the building. Conditions started to deteriorate, and all apparatus were ordered moved from the north side of the building, since this part of the fire lane was within the collapse zone. Truck 8, which had been operating along this part of the fire lane, malfunctioned for a short time with its aerial extended and narrowly escaped damage.
At this point, operations went totally defensive with multiple master stream devices. There were no immediate exposure concerns. With the sprinkler system already flowing massive amounts of water, engine companies reported some problems with trying to maintain adequate pressure while supplying master stream devices. Mutual-aid units started to return to service 4:00 a.m.; the last Grand Prairie unit cleared the scene at 8:00 a.m. on February 12.
The Grand Prairie Fire Department (GPFD) Arson Division’s final investigative report indicated the cause of the fire could not be determined. Based on an interview with an employee immediately after the fire, the investigator concluded the fire was probably started from the overhead lights, which had been the cause of previous fires. Investigators were able to locate all lighting fixtures in the area of the fire and determined they were not an ignition source. In addition, fire department records did not show any previous fires at the address where lighting fixtures were listed as the fire cause. The estimated loss to the building and contents was $7.4 million.
CLOSER LOOK AT VENTILATION IN SPRINKLERED WAREHOUSES
According to the National Fire Protection Association (NFPA) Fire Journal, Lisa Nadile, in an article in the March/April 2009 issue, describes a large-loss fire in a Tupperware warehouse in Hemingway, South Carolina, on December 11, 2007. This fire highlighted the complications that can arise when attempting to extinguish a working fire in a warehouse with high piled storage. The Tupperware fire situation mirrored the Grand Prairie fire in several areas:
- A fully functional sprinkler system controlled the fire, but final extinguishment was left up to the fire department.
- Firefighters had a difficult time operating in the maze of narrow aisles of the 160,000-square-foot building.
- Almost 17 hours into the incident, crews temporarily turned off the sprinkler system for 20 minutes to improve visibility so they could better locate the fire and remove some of the building’s metal skin to provide better access.
- Introducing outside air allowed the fire to progress out of control, and the building was a total loss.
Throughout the Grand Prairie incident, a major emphasis was placed on ventilating the warehouse. Although firefighters making interior attacks on the fire faced no significant heat conditions, they were constantly operating in near-zero visibility conditions because of the dense white fog-like smoke typically produced in these situations. Therefore, ventilation was seen as necessary to completing final extinguishment. Despite all efforts by the fire departments to provide adequate ventilation, visibility never improved. This included bringing a large truck-mounted fan from the airport and operating it for approximately one hour as well as attempting to manually operate the wall-mounted smoke evacuation fans.
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| (4) This photo was taken a month and a half after the fire. |
Whether the wall-mounted smoke evacuation fans ever worked is unknown. At some point as the fire grew, the fans would have become ineffective. The number and capacity of the fans had been reduced during the design phase because of the installation of the ESFR sprinkler system. The reasoning was based on the small size of the fire expected because of the quick response of the ESFR sprinkler heads. However, since the ESFR heads had been removed in the area of the fire’s origin, the actual fire size was much larger than expected, and the existing smoke evacuation fans would not have been able to keep up with the smoke production.
Even if the fans were adequate, would you still want to use them if you have a fire that is not totally extinguished by the sprinkler systems? The answer may not always be yes. NFPA 13E, Recommended Practice for Fire Department Operations in Properties Protected by Sprinkler and Standpipe Systems, Section 4.6.1, states the following:
- Fire department personnel should study occupancies with a wide variety of configurations and storage commodities to determine whether there is a need for special procedures, particularly where storage heights are in excess of 12 feet because, in some cases, routine ventilation procedures in the early stages of a fire can hinder effective sprinkler operation. The fire department should discuss its preincident plan for these type occupancies with the occupant, sprinkler designer, and insurance carrier to determine whether a modification in procedures is appropriate.
- Section 4.6.2 adds:
- Where search and rescue operations have been completed prior to the fire department’s performance of ventilation work, the incident commander should allow the automatic sprinklers to continue to operate without further ventilation.
Factory Mutual Insurance, the leader in insuring warehouse occupancies, has similar information in its Data Sheet 1-10 involving ventilation. It basically warns that the use of significant ventilation, by whatever means, can be detrimental to effective sprinkler operation. It also recommends that mechanical smoke ventilation be used only after the fire has been placed under control. Too much air movement can cause the fire to spread and exceed the capability of the sprinkler system. And, as this fire showed, all your best efforts at ventilation may not move the smoke; that’s just the nature of how sprinklers work. That is the reason TICs are becoming critical to firefighters operating in these structures.
STORAGE CONFIGURATION
One of the baffling facts that came out of this fire involved the area of origin. The material stored in this area was noncombustible empty soda cans, so how could a fire originating in this area with an automatic sprinkler system lead to such devastating results?
After the fire, arson personnel performed a very informal small-scale test using the plastic slip sheet material used between and on top of the rows of empty soda cans. As the fire moved horizontally across the sheet, investigators reported that the burning melting plastic was dripping onto the items below, rapidly creating secondary fires. This included the ignition of a plastic pallet that burned for approximately one hour until it was extinguished with water. The testing also showed that when water was introduced to the plastic slip sheet, the fire increased in height and removal of the water resulted in rapid reignition of the molten material. It was also noted that the cans seemed to act as a shield that prevented water from reaching the slip sheet. When water was introduced on one side of the can pile, it appeared to push the fire out the opposite side of the pile.
Although the exact ignition source could not be determined, it is believed that a plastic slip sheet ignited near the top of one of empty can piles. As the fire intensified, it rapidly started fires on the sheets below, and the fire also started traveling horizontally. As the fire dropped lower and lower into the can piles, it probably became more difficult for the droplets from the standard sprinkler head to penetrate the pile and reach the spreading fire. The empty cans themselves also appeared to contribute to shielding the fire from sprinklers. When enough of the interior slip sheets had burned away in a given pile, it caused the pile to become unstable and eventually collapse. This scenario could be compared to burning a pile of wooden crates—lots of combustible surface area and lots of air spaces to supply oxygen.
SPRINKLER PERFORMANCE
Initial fireground reports indicated there was some question as to whether the sprinklers were operating effectively. At least one fire company reported that the sprinklers could be heard but not seen in operation, which would indicate possible sprinkler obstructions. Later, internal interviews by the GPFD concluded that most firefighters recalled the sprinklers operating as expected. The final report by the fire department indicated the actual storage height was more than 27 feet, which could have put the storage up against the bottom chord of the bar-joist assembly in some areas. Depending on the exact storage height in the area of fire origin, this could have had a negative impact on the sprinkler discharge pattern.
Based on available documentation, the sprinkler system in place where the fire originated was not an ESFR system. Although the piping was based on an ESFR design, the ESFR type sprinkler heads had been replaced with extra large orifice heads. Hydraulic calculations by the sprinkler designer showed the original ESFR sprinklers were designed to deliver a minimum flow of 121 gpm at 75 pounds per square inch (psi) to the most remote sprinkler. The extra large orifice heads in place at the time of the fire were designed to deliver a minimum flow of 63 gpm at 30 psi.
ATTACK METHODS AND CONTAINMENT
Another important lesson learned from this incident involves containment of the fire using handlines. We usually assume the sprinkler system will control the fire and keep it from spreading, and many times that’s true—but not always. In this case, the sprinkler heads had not been changed back to ESFR heads. Therefore, the heads being used were slower to respond to the fast-moving plastics fire and were trying to catch up to the fire. Even though it wasn’t obvious at the time of the fire, trying to contain the fire and keep it from jumping any aisles became critical. And firefighters were already at a disadvantage because the first interior attack wasn’t initiated until 38 minutes after the initial alarm. As the fire grew, they were continuously deluged with falling soda cans and pallets.
Containment of the fire was likely lost when firefighters pulled out of the building after the first interior attack to allow the aerial master stream to operate in the bay door. Thirty-five minutes elapsed from the time the first attack team left the building until the second attack team went back into the building. This second attack team reported it could not return to its original location because of additional fallen cans littering the aisles—thus confirming the fire had continued to spread after the first attack ceased, causing additional piles to become unstable and collapse. Trying to maintain containment in this situation would have been difficult considering the collapsing cans and pallets.
At 11:28 p.m., AFD Quint 1 gave an approximate location of where it observed fire. Based on this information, the fire had traveled 56 feet in almost four hours. However, around 2:00 a.m., conditions started to deteriorate as too many heads were flowing and the fire started to overtake the sprinkler system.
In hindsight, the use of Truck 1’s aerial stream into the bay door was not the best strategy to employ at the time because of its low probability of success. It may have possibly prevented the fire from being contained, and any air entrained by the stream could possibly have pushed the fire into unburned areas. At the very least, the stream itself likely knocked even more cans into the aisles, creating even more obstacles for firefighters trying to reach the seat of the fire.
PERSONNEL AND RESOURCES
For a small fire in a warehouse close to the ground, a large personnel commitment is not always required. But for this fire in particular, a large force was needed in the early stages to maintain containment. As more time passed, the fire was traveling horizontally in all directions. As more and more piles became unstable and collapsed, firefighters had an increasingly difficult time getting close to the fire because of the massive number of cans on the ground. Therefore, this fire had to be contained during the early stages with multiple handlines attacking the fire on multiple fronts, with the primary focus being to limit the fire’s spread.
Another aspect to consider is what type of search and rescue operations to conduct on a building of this size. The building had more than 100 occupants when the fire started, and there are reports that some of them were reluctant to leave, especially since the fire alarm had been sounding throughout the day as technicians had been working on the fire protection systems. In the case of this fire, off-duty fire prevention personnel responding on the multiple alarms coordinated with employees with respect to accounting for all individuals in the building at the time of the fire. There was no primary or secondary search.
In Grand Prairie, the overwhelming majority of structure fires that occur in the city are in single-family residences. Therefore, the multiple-alarm assignments reflect this fact. The second alarm for this fire brought an engine, a truck, and an ambulance with nine additional personnel. These personnel, along with the 15 personnel from the first-alarm assignment, battled the fire for the first two hours, which turned out to be the most critical. The third alarm brought two engines and a quint, and the fourth alarm brought two engines. Departments with similar multiple-alarm assignments may want to consider adding additional companies to each alarm, particularly for commercial structure fires. This may require extensive mutual aid and back-filling of empty stations, but the personnel will be available when needed.
One of the biggest problems on the fireground involved radio communications using the city’s digital radio system. Communications with portable radios anywhere in the vicinity of the fire were virtually nonexistent. The portables could transmit to the repeater tower, but they picked up so much background noise that command could never understand any of the radio transmissions from the interior. Any message had to be delivered by a face-to-face conference at an exterior door or by sending a runner. In either case, valuable time was lost. This incident proved that any gains made in interoperability using the digital radio system were far outweighed by the inability to communicate on the fireground. When the firefighters became trapped by falling debris, no Mayday signal was transmitted over the radio.
LESSONS LEARNED AND REINFORCED
• The best way to stay out of a potential large-loss fire involving a warehouse with high piled storage is to implement aggressive inspection measures to reduce the chances that the sprinkler system may be compromised. This includes multiple inspections and/or walk-throughs to ensure proper storage height, storage arrangements, and commodity classification. Many large-loss warehouse fires are the result of improper storage arrangements, particularly storage piled too high so that it blocks the sprinkler spray pattern. At the time of this fire, there were no regularly scheduled fire inspections for the building following the initial inspection when the Certificate of Occupancy was issued. Although there were some questions as to whether the sprinkler system was compromised immediately after the fire, this issue could not be verified.
• Use an ESFR sprinkler system whenever possible to increase the chances that the sprinkler system will extinguish the fire with minimal fire department involvement. The extra large orifice heads did their job of initially controlling the fire until the fire department arrived, but they did not extinguish the fire.
• Develop a way to track variances for each building to evaluate them as the building occupants change. The two initial variances for the building should have been reevaluated once the ESFR system was removed because each variance was totally dependent on the ESFR system’s being present. When the carpet company left and the distribution company moved in, this could have provided the emphasis for reinstalling the ESFR heads to avoid reopening the variance issues.
• Operate a master stream into a sprinklered building during the early stages of an incident only as a last resort if conditions have already deteriorated to the point that an interior attack is not possible.
• When fighting fires in high piled storage occupancies, you will likely need multiple TICs to aid interior crews in directing streams in near-zero visibility conditions.
• Effective ventilation options to improve visibility are extremely limited for a working fire in this type of occupancy. You may have to get accustomed to operating in very limited visibility. Take extra precautions to ensure firefighters do not become lost in the vast spaces of the warehouse. If ventilation is necessary to remove excessive heat at the roof level, the sprinklers are not doing their job, and interior operations may not be safe.
• Plan any significant ventilation efforts in advance based on the specific occupancy conditions. Significant ventilation during the early stages of the fire can have a negative impact on sprinkler performance. Using mechanical exhaust fans is generally recommended for mop-up operations only.
• Fires in sprinklered buildings can bring about a sense of security because of their high success rates. Follow all normal fireground protocols. In this incident, normal personnel accountability reports and rehabilitation policies were not followed.
• Arrange a fuel source in advance for fire apparatus for long-duration incidents such as this one. By daybreak, some companies started to run low on fuel, prompting officials to search for a fuel source.
• Give priority to making the hookup to the FDC. Command may want to consider keeping the engine crew together until this task is completed. In this fire, it took 16 minutes to complete this task. Had the fire pump been impaired, completing this task would have been critical.
• Records show that when the distribution company moved into the eastern half of the building, the sprinkler system was never reevaluated to determine compliance with respect to the new tenant’s storage arrangement. No record specifying a new maximum storage height could be located. This evaluation must take place any time there is an occupancy change involving high piled storage.
• Establish regular testing intervals for all fire protection systems in a given building. In Texas, there are annual testing requirements for fire suppression and alarm systems, but smoke exhaust systems are not included in this statute. Firefighters could not determine if the smoke exhaust fans in this building were working, even when using the manual controls. Local amendments requiring regular testing of all smoke-control systems should be added. Records of all required testing should be kept on file with the fire department.
• If an interior attack is going to be made on a stubborn fire in a high piled storage occupancy, it must be made on multiple fronts to keep the fire from spreading. This will require extra personnel such that an identical number of fresh crews are available to relieve interior crews when they start running low on air so that containment is not lost at any time.
• When preplanning, take into account obstacles that will be encountered during a fire attack. In this fire, firefighters were constantly bombarded by falling soda cans and plastic pallets.
• The problem of hand-held radios picking up too much background noise during firefighting operations cannot be overemphasized. Radios were of extremely limited use for crews operating in the vicinity of the fire. Face-to-face meetings or runners were usually required to get messages delivered. This issue must be addressed since more and more jurisdictions are switching to digital radio systems.
• Review the number of units assigned to each multiple alarm, especially for large commercial occupancies. Although the first alarm for this fire consisted of three engines and one truck, the second alarm consisted of only one engine and one truck. The third alarm consisted of two engines and one quint, whereas the fourth alarm consisted of two engines.
• The fire alarm system for this building consisted of at least three different systems/panels. The preferred arrangement would have been to have one main addressable panel and, if needed, subpanels in the tenant spaces.
• The fire alarm system for the building had experienced problems in the past and was reported not to have been functioning properly at the time of the fire. The alarm company received a burglar alarm notification; only after calling an on-site employee was it determined that the building might be on fire. The fire alarm system, even if it’s just monitoring water-flow switches, is crucial to providing early notification to the fire department. Proper plans and follow-up inspections are crucial to ensure the system will work as intended.
• Technical difficulties with fire apparatus on the fireground can put firefighters at risk. Crews were trying to relocate Truck 8 out of the collapse zone as conditions were quickly deteriorating. This was the second time the truck malfunctioned during this incident.
• Normally, checking with an employee on arrival will allow firefighters to better pinpoint where the fire is in a large building. In this case, just the opposite was true. The original call gave the correct location of the fire, whereas the employee who met arriving companies directed them to the wrong location, thus delaying firefighters from reaching the seat of the fire.
• Consider the size and scope of search and rescue operations for a building of this size. Quickly summon extra personnel, if needed.
• Although the fire lane met local codes, the entire north side of it was within the collapse zone. When the collapse zone was established, it created two long dead-end fire lanes.
• Be careful about opening overhead doors prior to determining what type of fire situation is present. A strong wind in a particular direction could possibly spread the fire before attack lines can be placed in service.
• The command post location changed several times during the incident. In addition, command was passed to a higher-ranking officer on two occasions. During the incident, the letter designations for each side of the building did not stay consistent, causing some confusion on the fireground. The letter designations must remain consistent for the duration of the incident based on predetermined guidelines.
• If you have high piled storage warehouses in your district, begin brainstorming now about the methods and procedures you wish to implement should you face a fire where the sprinkler system is controlling but not extinguishing the fire or if the sprinkler system is impaired in some fashion.
• Maintain accountability at all times. If accountability is lost, valuable time can be lost while companies reorganize.
• Once the building becomes fully involved and is written off, try to close the affected sprinkler valves if you can do so safely. Post indicating valves or main control valves at the loop connection can help you accomplish this action so that adequate water will be available to protect exposures.
You may read this article and come away with the impression that it deals more with code issues than firefighting tactics—and you would be right. But as recent fires have shown, the sprinkler system will not totally extinguish all fires. The common thread between the Tupperware fire and the Grand Prairie fire is that firefighters felt an extreme sense of frustration after battling the fire for many hours with no noticeable progress. Trying to move from the control phase to the complete extinguishment phase was a daunting task in both fires.
For large warehouses in general, the fire service is going to have to obtain a broader knowledge of fire protection systems and the concepts behind them to better formulate attack methods and ensure firefighter safety. The fire service must reevaluate ventilation for these types of occupancies because procedures that work well in other occupancies do not necessarily work well in warehouse occupancies.
Start planning now for a scenario similar to the Tupperware and Grand Prairie fires because an endless number of standard sprinkler systems are designed to control a fire instead of extinguish it. Because of the excellent record of sprinkler systems, we don’t really think of having to distinguish between control and extinguishment. These two fires demonstrate that a difference does exist and that fire departments must be prepared for it.
JEFFREY A. HARWELL is a fire protection engineer based in Burleson, Texas.
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