THE IMPORTANCE OF NFPA 921: A DOCUMENTED CASE
BY AND
NFPA 921, Fire and Explosion Investigations Guide, formally adopted in 1992, stresses the importance of using a systematic approach to fire investigation. It not only serves as a fire investigation guide but also provides improved scientific concepts to assist fire investigators in eliminating long-standing misconceptions and outdated practices that can lead to erroneous conclusions.
The following fire incident shows the importance of following the procedures outlined in NFPA 921. Had the original investigators in the scenario below followed its basic tenets, they would not have arrived at erroneous conclusions that placed unnecessary hardship on the homeowner.
THE INCIDENT
In the early morning of November 14, 1989, a man, while letting his dog outside, noticed smoke coming from his neighbor’s house. The volunteer fire department responded to an alarm sounded at 4:18 a m. According to the fire department report, the firefighters did not see any flames or smoke by looking directly through the windows on the first level, although smoke was bellowing from the roof.
The nearest hydrant was located on an adjacent street approximately a half mile away, which delayed the start of the water-supply operation somewhat. Nevertheless, most of the house was saved. The roof had sustained the greatest damage.
The neighbor who reported the fire said that the owner, who was from out of town and had been in town to do some painting and minor repairs, had just left the residence. The owner of the home returned during the fire extinguishing efforts. He said he had left to go to a local “all night” coffee and donut shop and returned when he saw the fire engines going down the street on which his rental residence was located.
The neighbor’s and owner’s statements were included in the fire department investigation report. (The fire department’s investigation followed the extinguishment of the fire.) The fire department ultimately classified the fire as incendiary, but no charges or arrests were made.
A short time later, private origin and cause experts were sent to the scene by the insurance company to investigate the fire. They also concluded that the fire was incendiary, and the insurance company denied payment to the insured.
Approximately a year and a half later, the attorney representing the insured requested an independent investigation of the fire scene to verify the findings and conclusions of the previous investigators. The house had not been restored from its fire-damaged state.
These independent investigators eventually found interesting facts at the scene that did not correspond with the previous investigation reports. In the first place, the insurance company investigators indicated in their report and deposition that they examined the air-conditioning unit located in the HVAC closet, where the fire originated. They reported that they had examined all of the electrical components within the A/C unit and could find no indication of a malfunction. This could not have been the case, however, because the independent fire investigators subsequently found the rotor of the single-phase motor still in place. The metal alloy “bell housing” had melted, and all three pieces had coagulated into one assembly. This rotor would not rotate; and an examination of the rotor stator, rear bearing, and centrifugal switch would have been impossible without disturbing this coagulated assembly.
Another disputed finding stated in the local fire department’s and insurance company’s investigations was that an accelerant had been poured into the HVAC closet and that it had extended into the living room, causing the carpet and pad to burn away. They also claimed that a flammable liquid ignited on the surface of the floor had caused the terrazzo floor beneath the A/C unit to spall. This conclusion by the local fire department and insurance company investigators was upheld even though laboratory tests conducted with samples taken from numerous locations within the house detected no accelerant residues. Contrary to NFFA 921, these fire investigators failed to take control samples.
Ihe independent investigators for the homeowner had photographic evidence of debris as high as two feet in the area that previous investigators’ photographs had identified as the location at which the carpet and pad had burned. This debris originally had come from the wood closet door itself and the roof structure above the closet area. In addition, burn patterns showed extensive charring on the “inside” face of the door (the side of the door facing the A/C unit). The evidence was uncovered when the independent investigators were allowed to view the photographs taken by the local fire investigators at the scene immediately after the fire and before the debris was removed. The falling hot debris obviously had melted and burned away carpet and pad during the fire and shortly thereafter.
The independent investigators also found a drain hole in the center of the HVAC closet floor and determined that no significant quantity of flammable liquid would have been allowed to accumulate; most of the accelerant would have drained away. Moreover, the significant pitch of the floor would not have allowed a flammable liquid to flow into the living room area. In addition, it was determined after close examination that the wood base plates in the HVAC closet next to the floor showed no signs of burning. However, the inside of the studs between the drywall sheets showed charring on the top. This burn pattern was attributed to the roofing materials’ falling between the walls, since burnt roofing materials were found between the drywall sheets.
The original investigators also claimed that a second fire had originated in the kitchen area and that the linoleum floor was pitted with bum marks from an accelerant. The independent fire investigators conducted a kitchen floor slope flow test and found that water ran to an area of the baseboard that was unaffected by any fire. They also removed the base of the kitchen cabinet area, which sustained the heaviest damage. The top of the cabinet had suffered direct fire damage, but the bottom underside was clean and clear, indicating no low burning, which would have been the case had flammable liquids been present. The independent fire investigators also performed a burn test using gasoline on the linoleum floor in the actual kitchen. They chose an area that had not been affected by the fire. The test showed that when the gasoline was ignited, it burned quickly enough so as not to “pit” or substantially mark the linoleum, as was the case with the linoleum in the kitchen area affected by the actual fire. The independent fire investigators concluded that the actual burn marks on the kitchen linoleum floor were caused by burning debris falling down from the roof area-not by a flammable liquid. The dishwasher in the kitchen, which previously had not been examined internally, according to deposition testimony, showed that the heat affected the inside of the dishwasher from the rear, the wall that was shared with the HVAC closet-the originating point of the fire. The fire then extended into the roof and the wall separating the HVAC closet and the kitchen.
The independent investigators further examined the underside of the kitchen cabinets, the underside of the | dishwasher, and the cove molding ‘that went around the perimeter of the (kitchen -all showed no burning [whatsoever. These investigators also found that while the electrical service panel cover had been removed, the breakers had not been removed or examined. Furthermore, the branch (circuits leading out of the service panel into the attic area had not been examined either. In addition, the original investigators had not made a report of the circuit breaker’s status (position).
ANALYSIS
Had the original investigators followed the guidelines of NFPA 921 (and NFPA 907M, Investigation of Fires of Electrical Origin-1988) when investigating this fire, they would have reached an entirely different conclusion. NFPA 921 clearly states that an investigator should use a systematic approach when investigating a fire and should, whenever possible, test the hypothesis. Had this been done in this case, the theorized second point of fire origin on the kitchen linoleum floor never would have been an issue.
- In this case, the electrical appliances in lower counter space areas adjacent to the HVAC room should have been examined even though there was no strong indication that they had been directly involved in the fire. In this case, the independent investigators found that the inside of the dishwasher gave clear evidence pertaining to the fire’s direction of travel.
- The spalling of the terrazzo flooring in the HVAC closet area should not have been automatically attributed to the pouring of an accelerant. As NFPA 921 clearly states, there are other causes of spalling. In fact, after the Bureau of Alcohol, Tobacco and Firearms examined die homes involved in the Oakland, California, wildland fire of 1991, it concluded that spalling is likely to occur when concrete is exposed to rapid heating from almost any source of burning material that produces heat. Also, concrete commonly spalls during firefighters’ extinguishing efforts due to the rapid cooling of the surface when it is hit with water.
In view of these findings, the independent investigators concluded that this fire should have been classified as one of unknown cause, with the origin being in the roof area above the HVAC closet. Failing to follow some of the basic concepts contained in NFPA 921 led the original fire investigators to erroneously conclude that there were two separate points of fire origin and that a flammable liquid had been used. Consequently, an innocent homeowner was almost denied payment on his insurance policy. As a result of the independent investigators’ findings and a jury trial, the insurance company had to pay not only more than the amount due on the policy but also for court costs, attorney fees, and expert witnesses fees/costs.
