Fire Pattern

Evidence of Origin

Particularly in cases of limited burn damage, the pattern of fire damage can be indicative of the fire origin. The more extensive the damage, the less precise the information is likely to be and the larger the identified area of possible origin. The photographs that follow on this page and others in this section will give examples of the interpretation of overall fire pattern ("macro" features) and of fire damage to individual components ("micro" features).

Burn pattern on underside of BMW hood, showing heat concentration near rear of engine and on right side. Forward on vehicle is up and left in photograph.

 

The lighter area in the burn pattern on this Ford F150 correlates to the likely location of the origin of the fire. For more details about this case, click here.

 

A collision damaged the valve cover of the Ford Escort pictured above, allowing oil to leak onto the hot exhaust manifold and ignite. Burn damage was limited such that the only evidence of fire was in the region of the exhaust manifold. For more about this fire, click here.

The investigator should also be aware that in instances of significant burn damage, and even in some cases of limited burn damage, the “hot spot” is not a function of the point of fire origin, but can instead be due to the location with the greatest fuel load. If the fire begins in a region with relatively little consumable material and then propagates to an area with a large amount of flammable liquid or combustible polymer, the secondary area will appear to be the hot spot.

This 1994 Saturn SL2 was subject to rear-end impact, fuel tank damage and immediate fire. The most likely location of fire origin was adjacent to tank damage under the passenger compartment, but the fire quickly propagated through splits in the body sheet metal and burned the interior.

Close-up view of gas tank through split body panels.

The hottest fire burned in the interior, which would mislead the investigator as to the origin unless taken in context of all information. For more on this fire click here.

This metal tank in the following picture was punctured when the driver drove over a tow dolly, spilling gasoline on the pavement and initiating a pool fire under the vehicle. In this case, the origin would be under the vehicle.

Gas tank punctured by tow dolly which led to a pool fire. For more about this fire, click here.