Establishing the Cause of a Fire Through the Process of Elimination 

Subrogation & Recovery Alert

August 5, 2013

In 2011, the National Fire Protection Association (NFPA) explicitly rejected negative corpus as a reliable methodology in fire investigation. Specifically, NFPA 921-18.6.5 provides:

The process of determining the ignition source for a fire, by eliminating all ignition sources found, known, or believed to have been present in the area of origin, and then claiming such methodology is proof of an ignition source for which there is no evidence of its existence, is referred to by some investigators as “negative corpus” …. This process is not consistent with the Scientific Method, is inappropriate, and should not be used because it generates un-testable hypotheses and may result in incorrect determinations of the ignition source and first fuel ignited. Any hypothesis formulated for the casual factors (e.g., first fuel, ignition source, and ignition sequence), must be based on facts. Those facts are derived from evidence, observations, calculations, experiments and the laws of science. Speculative information cannot be included in the analysis.

Section 18.6.5 presents a significant obstacle to subrogation actions when a fire’s ignition source cannot be conclusively determined due to the damage caused by the fire, particularly when it is believed that the fire was caused by a discarded cigarette. However, a recent decision in a case being handled by Cozen O’Connor from the U.S. District Court for the Southern District of Ohio may serve as valuable precedent in such circumstances. See Zurich American Insurance Company v. The O.W. Taylor, LLC, Case No. 1:11-cv-108 (S.D. Ohio July 1, 2013).

The case involved a fire that occurred in a building undergoing renovations. Zurich provided insurance for the owner and developer of the building. Zurich filed a subrogation action against O.W. Taylor, a company that provided contracting services at the building at the time of the fire. Zurich alleged that the fire was caused by a cigarette that was carelessly discarded by one of O.W. Taylor’s employees. In support of its allegations, Zurich relied on testimony from: (1) Daniel Wolf, a member of the Cincinnati Fire Department’s investigation team; (2) Kerry Autio, a cause and origin investigator hired by Zurich; and (3) Craig Beyler, an expert hired by Zurich to rebut the testimony of O.W. Taylor’s expert.

O.W. Taylor filed a motion in limine to exclude the opinions of Wolf, Autio and Beyler, alleging that: (1) the opinions were based on the absence of evidence, rather than the presence of facts to support their conclusions and (2) the opinions were based on the unreliable methodology of negative corpus. The court denied the motion.

With respect to the first allegation, O.W. Taylor argued that the experts’ opinions were based on a series of inferences that were not supported by the factual record. Specifically, O.W. Taylor alleged there was no evidence that its employee was smoking in the area of origin on the day the fire started. The court dismissed this argument, finding that there was sufficient evidence to support the experts’ opinions. Specifically, the court noted: (1) the employee testified that he was a smoker; (2) the employee testified that he regularly smoked a pack of cigarettes a day; (3) the employee admitted that he had previously smoked while on the job in the building in which the fire occurred; (4) the employee testified that he may have extinguished his cigarettes on the floor, but that he tried to pick up the cigarette butts; (5) the employee was the only smoker on the crew; (6) the employee was working in the area of origin on the day the fire started; (7) two of the three investigators ruled out other potential ignition sources in the area of origin; (8) there was no electricity in the area of origin; and (9) there was evidence that the building was secure. The court concluded: “although there is no direct physical evidence of a discarded cigarette at the origin of the fire, the Court finds that the other evidence of record provided a sufficient factual foundation on which to develop a causation hypothesis that involved a cigarette being discarded by [the employee].”

The court went on to address O.W. Taylor’s allegation with respect to negative corpus. In support of its argument, O.W. Taylor relied on NFPA 921-18.6.5. According to O.W. Taylor, NFPA 921 explicitly rejected the use of negative corpus to establish the cause of the fire. In response, Zurich argued that negative corpus was a different concept than the process of elimination outlined in NFPA 921, which specifically sets forth guidelines for when a fire investigator can use the process of elimination.

Ultimately, the court disagreed with O.W. Taylor’s argument that the methodology used by the experts to reach their opinions constituted negative corpus. In reaching its decision, the court made three significant findings. First, the court found that it is appropriate to use the process of elimination when the area of origin is clearly defined. Second, the court recognized that the process of elimination plays a legitimate and integral role under NFPA 921 for selecting a final hypothesis that is then analyzed by the expert based on his or her knowledge and experience. Finally, the court held that “cognitive testing is a sound methodology.”

The court concluded: “While there may not be physical evidence of a discarded cigarette at the point of origin, there is sufficient evidence of record on which the experts relied to eliminate other potential causes and to formulate a cause hypothesis based on a discarded cigarette. That hypothesis was also adequately tested by the experts prior to rendering their opinions. For these reasons, the Court holds that the three opinions on the cause of the fire were based on a reliable methodology and a reliable application of the facts to the present case.”

Although Section 18.6.5 may present significant difficulty in certain cases, the court’s decision in Zurich American Insurance Company v. The O.W. Taylor, LLC provides valuable precedent that may enable a subrogation professional to obtain a recovery.


Stacie M. Evans


(215) 665-7271

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