At the back of nearly every homeowner's mind lies the fear of an unexpected house fire, especially one that starts in the middle of the night when residents are sleeping. When you look at industry statistics related to residential fires in the United States, this fear is certainly not unfounded. In 2003, for example, someone died in a fire about every 2 hours and was injured every 29 minutes, according to statistics from the National Center for Injury Prevention Control, a branch of the Centers for Disease Control and Prevention (CDC). This group's research also reveals that fire departments responded to 402,000 home fires that same year, which claimed the lives of 3,145 people (not including firefighters), injured another 14,075, and cost more than $6 billion in property damage.

At approximately 2:25 a.m. one October night, this fear turned to reality for an unsuspecting homeowner when his house caught fire (Photo 1) and burned to the ground, resulting in total loss of the property. Although devastating and unfortunate, the home was unoccupied at the time of the incident, so luckily no one was injured.

After the accident, the homeowner (plaintiff) retained a professor of electrical engineering to uncover the cause of the fire. The plaintiff's expert witness alleged that the fire had been caused when the electric service conductors shorted together in the conduit at the point where the 4/0 aluminum electric service conductors went through the wall of the basement on the Southeast corner of the house (Photo 2 above). Furthermore, he believed the resulting arcing set fire to the house and blew the transformer fuse, which shut off the power to this house and the neighbor's house.

Based on this expert witness' testimony — that the conductors either had defective insulation upon installation or that the insulation was damaged during installation — the plaintiff ultimately filed suit against the electrical contractor that had installed the service entrance cable, holding this firm responsible for the cable failure and resultant fire.

The electrical contractor (defendant) retained my electrical forensic services to prove otherwise. In the end, not only did I prove that the fire did not start where the plaintiff's expert alleged, but also that the cause was arson, which removed all liability from my client.

Investigation details and analysis

Because there are so many combinations of possibilities for the cause of residential fires, I entered the investigation with an open mind, realizing that the fire may have started from a number of common culprits, such as a defective electrical installation, defective electrical appliance, or hot gases leaking from an appliance and igniting surrounding combustibles.

When I first examined the house, I found only the central chimney and the basement cap remaining. After reviewing the existing evidence, my investigation disclosed that there were obvious indicators of arson in the remains of the building. Specifically, saddle burns were found in several locations (Photo 3 below and Photo 4 on page 20).

Saddle burns normally occur when a flammable liquid is allowed to drip downward from the floor above and onto the floor joist or beam underneath. The flammable liquid soaks into the wooden joist or beam and burns the wooden member away in the characteristic pattern resembling a horse's saddle. Presence of saddle burns was a strong indication that a flammable liquid fire had been spread throughout the house.

The saddle burn in Photo 4 was almost textbook-like. Notice how the floor joist is directly beneath the butt-joined plywood sub-floor and the burn damage shows how the wooden floor joist had been burned away by the action of the flammable liquid dripping down onto the floor joist.

At this point in my fire investigation, my evidence led me to believe without a doubt that the fire was caused by flammable liquid and that the plaintiff's expert's theory was absolutely incorrect. My next step was to contact the responding fire department and determine if any photographs had been taken at the scene. Fortunately, a firefighter in the responding attack engine had taken several shots.

Conclusions and commentary

From my investigation, I drew several conclusions.

  • The fire originally started in the garage by a flammable liquid that was spread throughout several areas of the house.

  • The fire was incendiary in nature, meaning a person had deliberately set fire to the property.

  • Contrary to the plaintiff's expert witness, there was no defect in the service entrance cable to the house. In fact, the building's electrical system was not causative to the fire incident at all.

  • The electrical contractor caused no damage to the service entrance cable upon installation — his work was neither causative nor contributory to the fire.

As a result of my findings, the defendant denied all claims made by the plaintiff, who ultimately withdrew the lawsuit against the electrical contractor.

One of many lessons that can be learned from this case relates to proper investigative procedures. This incident was, first and foremost, a fire incident, but the cause of the fire had to be determined before any other decision could be made.

To properly investigate this incident, the plaintiff should have first determined the cause of the fire and, therefore, the initial investigator on the case should have been a fully trained fire investigator. Although the plaintiff's expert represented himself as an “electrical fire investigator” and electrical engineer, he had none of the common certifications typical of this type of expert, such as CFI (Certified Fire Investigator) from IAAI (International Association of Arson Investigators) or CFEI (Certified Fire & Explosion Investigator) from NAFI (National Association of Fire Investigators).

Failure to be properly trained in fire investigation rendered any opinion that plaintiff's expert expressed questionable because he failed to have the knowledge and training to form an opinion of the cause of the fire within a reasonable degree of scientific and engineering certainty.

Peserik, PE, PLS, CFEI, CFII, DABFET, is founder of James E. Peserik Associate Inc., a consulting forensic engineering and fire and accident investigation consulting firm based in Coopersburg, Pa.