A Tale of Two Origins

A Tale of Two Origins

by Rod Sanders, Fire Investigator, IAAI-CFI®, CFEI, CVFI

Applied Technical Services, Inc.

Most of us at one time or another have read the classic Charles Dickens novel, A Tale of Two Cities. The historical novel takes place during the French Revolution, set in London, England, and Paris, France. Both great cities are in Europe, but each are quite different. This article is about one fire investigation (Europe) and two fire origins (London and Paris) but the causes within each is quite different.

An early morning fire destroyed a popular South Florida restaurant. The insurer of the restaurant (plaintiffs) had retained fire and electrical experts to determine the origin and cause. Based on their investigation, the fire originated in the northeast corner of the kitchen and was caused by a specific failure in a capacitor located on the topside of a freezer. The freezer manufacturer (defendant) was put on notice of pending subrogation and 5-months after the fire, hired their own expert to determine the origin and cause of the fire.

In the evening prior to the fire, restaurant staff completed their normal closing duties. The last person to leave the business was the owner, at approximately 11:45 p.m. During subsequent interviews he reported nothing out of the ordinary prior to leaving. Approximately 4-hours after leaving at 3:37 a.m. he was notified by his alarm company of motion sensor activation in the kitchen. At the time of activation no one was aware of the fire. The owner responded to the restaurant within 10-minutes of notification. Upon arrival, he immediately noticed a smoke odor. He entered the restaurant through a rear door where he observed thick, black smoke and fire in the northeast corner of the kitchen.

The National Fire Protection Association developed NFPA 921, Guide for Fire and Explosion Investigations in 1992. It was developed to assist in the proper investigation of fires. Since then, there have been 8-revisions to the document with the 2017 edition being the most current. In the Basic Methodology chapter, the fire investigator learns that he/she should rely on the use of a systematic approach. The systematic approach that should be followed is the Scientific Method.

There are 7-steps in the Scientific Method: recognize the need, define the problem, collect data, analyze the data, develop hypotheses, test the hypotheses, and select final hypothesis to reach a conclusion to your investigation.

NFPA 921, 18.1 Introduction states, Generally, if the origin cannot be determined, the cause cannot be determined, and generally if the correct origin is not identified, the subsequent cause determination will also be incorrect.

If the Scientific Method is used properly, the fire investigator is less likely to miss important data used to select a final hypothesis. If mistakes are made during data collection, it can lead to misidentify the fire’s origin and possibly the fire’s cause. It is this author’s opinion that the opposing experts missed collecting critical data that ultimately led to misidentifying both the origin and the cause of the fire.

All the experts agreed that the fire originated in the northeast corner of the restaurant. However, one fire expert determined the fire originated on top of a freezer and the other fire expert inside the drum of a clothes dryer. Ultimately, it was through the data collection process that the correct fire origin was determined as well as the cause of the fire.

There were multiple potential ignition sources in the area of origin. The plaintiff’s experts primarily used fire pattern analysis to determine the fire origin. The problem was the area of origin reached full room involvement, so fire patterns developed during the incipient stage of the fire would no longer support their fire origin. Their emphasis on fire pattern analysis led them to eliminate all the other ignition sources except for the freezer.

During the defendant’s expert’s review of all the data, it was apparent that the evidence supported more than one hypothesis. Upon analysis of the data, the facts supported a final hypothesis that was very different than the one proposed by the plaintiff’s experts.

NFPA 921, 18.1.2 Introduction states, Determination of the origin of the fire involves the coordination of information derived from one or more of the following:

(1)  Witness Information and/or Electronic Data. The analysis of observations reported by persons who witnessed the fire or were aware of conditions present at the time of the fire as well as the analysis of electronic data such as security camera footage, alarm system activation, or other such data recorded in and around the time of the fire event

(2)  Fire Patterns. The analysis of effects and patterns left by the fire.

(3) Arc Mapping. The analysis of the location where the electrical arcing has caused damage and the documentation of the involved electrical circuits.

(4)  Fire Dynamics. The analysis of the fire dynamics [i.e., the physics and chemistry of fire initiation and growth and the interaction between the fire and the building’s systems.

In addition to fire pattern analysis, all the experts had access to witness statements, security camera footage, lab reports, and the fire dynamics.


As previously stated, the owner was the last person inside the restaurant prior to the fire. He told investigators there had been no problems associated with the appliances located in the area of origin. The freezer in question has operated properly since it was put into service. The clothes dryer had been in operation the evening prior to the fire but had automatically shut-off after its drying cycle. The contents were left inside the drum, remaining undisturbed. The owner stated that they only laundered hands and face towels on site. Any cloth materials that may contain cooking oils are laundered by an outside service.

Security Cameras

There were approximately 16-security cameras inside the business. One of the ceiling- mounted cameras in the kitchen captured the fire prior to the arrival of fire department personnel. The fire can be seen in the area of the dryer with no visible fire in the area of the freezer.

Lab Report

As part of the investigation, a request was made to collect the dryer and its contents for additional testing even though the plaintiff’s experts had eliminated the dryer as a fire cause. The contents (burned towels and aprons) were sent to a lab and tested for ignitable liquids and components that may spontaneously heat. The testing identified components on the materials that are subject to spontaneously heat.

Fire Patterns

A V-pattern was visible on the vertical surface of the drum opening and the contents of the drum were extensively burned throughout the pile.

Fire Dynamics

Unlike the freezer, all the elements required for combustion were present inside the drum of the dryer. A combustible fuel was present (cloth towels and aprons), oxidizer (air flow), and energy to initiate combustion (chemical reaction).

After an extensive investigation, the defendant’s expert determined the fire originated inside the drum of the clothes dryer. Oil contaminated towels and aprons underwent spontaneous heating and eventually spontaneous ignition. In addition, the defendant’s electrical expert found no evidence of a capacitor failure as alleged by the plaintiff’s experts.

The case was presented to a 6-member jury which returned with a defense verdict. For the defendant in this case it was the difference between paying or not paying $2.25 million in damages.

If you like to contact the author, Mr. Sanders may be reached at 678-797-3451 or by email at rsanders@atslab.com for more information about this subject.