Investigation of Collision Fires

The investigation of collision fires involves the same principles as those that apply to the investigation of non-collision fires, and each can be used to help study the other. All the same vehicle systems must be inspected and considered during an investigation. But when a collision is involved, on-board systems that were disturbed by collision provide clues to fire causation. In particular:

• Fluid systems can be breached and disrupted
• Electrical systems severed and circuits opened or shorted
• Flammable materials moved into contact with hot exhaust components
• High-impact or rollover collisions can disperse and/or spill flammable liquid fuels over a broad area
• Mechanical sparks from metal-to-metal or metal-to-pavement contact can provide additional ignition sources

If there is another vehicle involved, the fluids, electrical system, and exhaust components from that vehicle can become involved as well. It is not uncommon in a car-to-car collision fire that the first fuel ignited may be contributed by one vehicle while the source of ignition may be contributed by the other.

Compared to non-collision fires, there is obviously a lower likelihood of fraud or arson, especially for those cases involving substantial impact.