Attorneys initiate lawsuit after claiming a freezer/ice maker caused fire that partially burned down firm's offices and temporarily altered productivity.
After a fire almost completely dismantled a Washington D.C. law firm, the partners found themselves asking the same question: Why? And because the fire temporarily disrupted operations and destroyed records, as well as prompted partial rebuilding of the office, principals of the law firm began searching for answers immediately.
Since the fire seemed to stem from a freezer/ice cube maker located in a small kitchen, they assumed the culprit was malfunctioning electrical components. Based on this assumption, they proceeded to sue the freezer manufacturer. That's where forensic engineering comes in: to make sure all fingers are pointing in the right direction.
The freezer manufacturer's insurance company hired a forensic consulting engineering firm to get to the bottom of the electrical blame game. Since the consulting firm specialized in the forensic evaluation of evidence associated with accident investigations and major catastrophic events, it needed assistance to determine if an electrical phenomena associated with the freezer/ice cube maker caused or in any way induced the fire. No one at the firm had experience with electrical fires, so they asked for my assistance.
Examining the evidence. After reviewing photos taken at the site and other physical evidence, I visually inspected the freezer, which several experienced investigators had also disassembled and examined.
First, I checked the rear of the unit for fire damage. It housed the incoming electrical service, electrical wiring harness, and hermetically sealed motor. Conductors in this area had good electrical continuity, and the insulation was free of damage. The motor also had no fire damage and showed no traces of electrical faults.
After looking at the freezer and its components, I concluded its damage appeared to be secondary, which means fire damage had acted upon it but not caused it.
Interestingly enough, the part of the ice cube maker closest to the freezer door showed the most severe fire damage. Only part of the plastic ice cube maker (the part closest to the burned-away freezer door) appeared partially baked. Although scorched, insulation on the conductors that served the compressor's motor and control system had good integrity (the insulation was fully intact). The conductors had continuity with no evidence of electrical faults.
In the freezer's electrical control compartment, a conductor to a microswitch had what appeared to be four loose strands in a phase conductor. Apparently, the strands had not held firmly within a crimp connector. They showed no evidence of arcing (shorting to an adjacent ground). An internal phase-to-phase short in a single-phase 120V electrical feed wasn't possible, nor was an internal phase-to-neutral short. The strands were not close to any part that was at ground potential, nor at any other elevated potential.
Since each strand was at an equal voltage potential, there could not have been arcing between the strands. The only evidence of electrical arcing occurred after-the-fact: The external cord shorted out at the plug because of fire damage.
Circuit protection devices would prevent excess current. If the compressor's induction motor stalled on the freezer, the thermal overload in the unit would trip, and the branch circuit breaker feeding this circuit would have its thermal element actuate; tripping the breaker into an open-circuit mode and cutting off power to the freezer. An electrical fault would have opened the branch circuit breaker by tripping the magnetically actuated armature and cutting off power to the freezer.
With this in mind, the fire could not have started within the freezer because:
There was insufficient oxygen to sustain combustion.
The ice would have melted and probably extinguished the fire.
The insulation of the conductors was non-fire sustaining.
The fire was self-sustaining and fast burning. The gas pressure, caused by products of combustion, might have pushed the freezer door ajar, which it did not. A magnetic seal held this door. Therefore, I thought an internal freezer fire might have produced sufficient pressure to cause the door to open.
An internal fire would have consumed the entire plastic ice maker rather than partially char and melt only the front end of the unit.
Certain areas of the thermal insulation were somewhat scorched. But, the fire affected only those portions near the external surfaces of the freezer; not within the inner portion adjacent to the interior. In addition, the fire melted off the freezer's plastic door. It only damaged the ends of the front of the freezer, including a portion of the ice maker that protruded very close to the door. This indicated an external fire acting upon the freezer.
The report concluded a fire close to the freezer/ice cube maker swept up and around the front of the unit, consuming its door. It proceeded to engulf a countertop immediately above and adjacent to the freezer. However, it appeared it was a nearby wastepaper basket that caught fire, possibly caused by a discarded lit cigarette. It was this conflagration that swept up under the counter and over the freezer/ice cube maker, ultimately scorching the front of it severely.
The consulting firm submitted my investigative report, along with other evidence and photos, to the insurance company protecting the freezer manufacturer. Consequently, the consulting firm and its client selected me as an expert witness, should the law firm continue with the lawsuit. However, based upon the evidence submitted, the case ironically never made it to trial. The parties settled out of court in favor of the freezer manufacturer.