FIREFIGHTING IN RETAIL WAREHOUSES: THE BUILDERS SQUARE FIRE
At 15:56 hours on December 10, 1993, the Palm Beach County (FL) Fire Rescue (PBCFR) emergency communications center received a telephone report of a fire in the paint department of the Builders Square store in the Cross County Mall (followed quickly by a water-flow alarm reported by a central station). The nearly 20-year-old 425,000-squarc-foot mall, located in central Palm Beach County, encompasses several large core storesone of them the 89,000-square-foot Builders Square store, a multipurpose home/business hardware supply store.
The mall is fully sprinklered. The systems are supplied by an underground well. Two vertical turbine 1,000-gpm pumps serve the sprinkler systems and several privately maintained hydrants located on the property. One fire pump is an electric pump rated at 1,118 gpm at 86 psi; the other is diesel engine-driven and rated at 1.118 gpm at 85 psi. Both pumps are designed to operate in parallel. In addition, municipal hydrants also are located throughout the parking areas.
The entire mall is of noncombustible concrete block construction with a steel bar-joist roof covered by tar and gravel. I’he fire building has an open ceiling to the bar joists.
The Builders Square store has two wetpipe sprinkler systems as well as a dry-pipe system. The system protecting the fire area was designed as an ordinary-hazard pipe schedule system (estimates establish that the system was capable of providing approximately .29 gpm per square foot over an area of 6.000 square feet, the approximate si/.e of the fire area). The onehalf-inch. 286° upright sprinkler heads in the fire area (pendant heads under ducts) each cover an area of approximately 100 to 120 square feet. There were no in-rack sprinklers.
In addition to the sprinkler systems, the building also contained IJ^-inch hose stations as well as an alarm system with manual pull stations and smoke detectors. All systems were monitored by a central station.
RESPONSE
A normal first-alarm commercial response was dispatched to the fire site, 4346 Okeechobee Blvd.: two engines, a tower ladder, a rescue company, and a district chief. Members, arriving at the store within three minutes of the call, observed heavy black smoke coming from the front of the fire building. All store customers had evacuated the building; however, some employees were still inside and were quickly removed. The acting lieutenant established command and requested a second alarm, which brought three additional engines, two rescues (one to provide medical treatment and the other rehab), and one special operations unit; a district chief and a battalion chief; and several fire investigators.
The first-in engine crew caught the private hydrant in front of the fire structure and stretched a Di-inch handline initially charged off tank water into the building. On entering the store, the crew was met byhigh heat and dense black smoke. As they snaked around the store w ith the handline, they observed exploding paint cans and stock falling off shelves and that the sprinkler had activated.
Meanwhile, the driver/operator advised command that the hydrant was not Bowing water. (It was later learned that it had been shut off and the “roadway-box” valve had been asphalted over.) The second-arriving engine company was instructed to establish a continuous water supply from another hydrant at the rear of the store and supply the attack pumper.
District Chief Tom Phillips arrived shortly, assumed command, requested additional alarms, and expanded the incident command system. With numerous companies now arriving. Phillips quickly committed resources to a coordinated, aggressive attack. A crew was directed to vent the roof from a tower ladder, a backup line was ordered into the fire building, primary search for remaining occupants was undertaken. an additional line was stretched inside the adjacent exposure to prevent extension, and firefighters were sent to verify proper operation of the fire pumps. The fire department connection was not supplied for the duration of the fire.
Ventilation crews ascended to the roof. They did not observe any sagging, melting tar, or other significant roof-failure conditions. (They did note sponginess over the fire area.) They proceeded to open a ventilation hole over the fire area; in so doing, they noted a sprinkler head directly under the hole. The hole then was enlarged to 10 feet by 10 feet, to provide additional vent area farther from the operating sprinkler head.
The fire attack was delayed temporarily as the first crew ran out of hoseline before reaching the seat of the fire. Interior operations were slow and hazardous due to limited visibility and falling stock. Members inside located the controls for the building’s air-conditioning ventilation fan. The operations chief ordered that it be activated manually. This fan was engaged at about the same time the ventilation hole was completed. Positive-pressure ventilation also was used.
The combination of the ventilation fan and roof hole improved conditions significantly. Primary search was completed: it proved negative. Fire crews moved in on the seat of the fire, involving flammable liquids and paints. There were 497 gallons of flammable/combustible liquids in the immediate area of the fire (see box on page 37).
The flammable and combustible liquids were stored in open cases on the lower portions of metal racks, which had particleboard shelves. The racks were 18 feet high, with palletized storage in the upper portions. In addition, numerous stored aerosol cans exploded about 30 feet from the area of fire origin, creating heavy damage.
Fifty-six sprinklers had activated and were flowing water on the fire. These heads held the fire in check until final extinguishment by firefighters. A secondary search of the store also proved negative.
The fire was extinguished within 50 minutes of first notification. Command directed the sprinkler system be shut down but stationed a firefighter at the post indicator valve during overhaul operations and the fire investigation in case the fire rekindled. A blanket of AFFF, monitored by an engine company, was set down on the flammable liquid to protect the fire investigators.
Special operations units from PBCFR and the City of West Palm Beach monitored the area and runoff for contaminants. Drain areas were covered until runoff samples, also checked by the county health department, also on scene, were within normal limits.
Several additional alarms for personnel were sounded. Ultimately, 80 personnel responded.
INVESTIGATION REPORT
The investigation revealed that an employee was attempting to demonstrate that mineral spirits would not burn. After slicing a plastic container of mineral spirits with a knife and spilling one-half gallon, he made some attempts to ignite the liquid.
He then added sawdust to the spilled liquid and threw matches at it again; this time the spill ignited. The employees were unable to control the fire with extinguishers. Total loss in contents and property was estimated at $3.5 million. Builders Square has decided to relocate the store. The employee who set the fire was arrested, charged, and found guilty of two counts of culpable negligence.
BUILDERS SQUARE SITE PLAN
BUILDERS SQUARE FIRE—SPRINKLER ACTIVATIONS
The loss could have been much greater had not firefighters and the operating sprinkler system kept the fire confined to the general area of origin. Injuries were extremely minor: Two civilians suffered smoke inhalation, one firefighter twisted his knee, and a fire officer suffered a hernia.
LESSONS LEARNED/REINFORCED
- Retail stores with high-piled stock are now commonplace in many areas of the country. They present significant hazards, including high occupant loads in a warehouse environment; a wide mixture of hazardous stock, including such challenging materials as flammable liquids and Group A plastics; as well as the “mega” size of the building itself. Extensive preplans identifying specific concerns need to be developed. With the high occupancy turnover rate characteristic of such facilities, extra effort is required to ensure the accuracy of preplans.
- Flammable and combustible liquid storage can be extensive and difficult to control. Identification and possibly segregation provide special protection for these materials and can help minimize this codeenforcement headache. Plastic containers can make this headache a real migraine.
- The operation of 56 sprinklers is well beyond what most sprinkler systems are designed to handle—it is very possible that this building easily could have been destroyed. Higher sprinkler densities/design areas and a strong water supply, as well as thorough plan review and inspections for these types of buildings, are called for.
- Supplying the fire department connection is important and normally should be SOP for the firstor second-in engine company at such incidents. Fortunately, the large parallel fire pumps provided a good water supply to the system at this fire.
- Account for the need for long stretches around maze-like racks typical of these types of facilities. Heavy fire loading calls for larger handlines. After the Builders Square fire, PBCFR revised its SOPs for similar-type fires such that first-in attack crews stretch 500 feet of 2M-inch hose with a smooth-bore tip.
- The use of foam lines should be expected in facilities of this type because of the prevalence of flammable and combustible liquids.
- Operating on a high-piled stock building’s built-up roof with open-web steel trusses when a significant fire is underneath is a fairly dangerous operation. Roof condition; fire size, type, and location; and the ability of the sprinkler system to control the fire and cool the roof mcmhers are some factors that must be considered before sending personnel to the roof and must be continually monitored during the operation.
MATERIALS CONSUMED IN THE FIRE AREA
- Conducting primary searches with a significant fire underway will be difficult. It is important to establish from store management who is missing/unaccounted for. A building of this size with its “maze-like” rack arrangement makes search operations dangerous and finding victims in time very difficult. Use search lines when required.
- When extensive roadway work is underway in the area, fire hydrants must be checked for proper operation. Often, as in the case of this fire, road construction crews w ill shut down hydrants and forget to reopen them. These same crews often will pave right over the control valve supplying water to the hydrant.
- Thorough fire prevention efforts must be brought to bear by fire prevention personnel w hen stores of this type are initially constructed. Unfortunately, existing national fire protection standards are “behind the curve” and often do not adequately address the problems present in these types of buildings, including the following:
— Mixed storage arrangements. Some stores use palletized-rack storage on the upper tiers of the rack, boxed shelf storage in the middle, and open-display shelving near the floor. Shelving blocks water spray from automatic sprinklers, necessitating the use of wire mesh shelving or in-rack sprinklers. (Factory Mutual’s Loss Prevention Data Sheets provide the best guidance when dealing with shelving issues.)
— The long-standing requirement for draft curtains (and smoke “fans” or vents) found in some of the model fire codes. Draft curtains are particularly problematic in facilities of this type where rack layout changes are made for merchandising purposes. (Of course, the ongoing debate over the use of automatic smoke venting and draft curtains in “sprinklered” buildings still rages unabated with no resolution in sight.) How do draft curtains affect the operation of automatic sprinklers?
— Life-safety issues, particularly egress from the building. Why is the travel distance to an exit permitted to be the same for a sprinklered office building and a highpiled retail store? Can exits be easily identified in retail stores of this type during a fire?
— Mixed types of materials. The presence of high-challenge materials (such as Group A plastics) often necessitates that fire prevention personnel take a conservative approach and treat the entire high-piled stock area as the “worst” type of material (and usually at the greatest expense), irrespective of how much of the “worst” material is actually present. Model fire codes and standards offer little guidance on how to cost-effectively protect “mixed” storage.
