Wildland Fire Investigation, FI–210 Origin and Cause Determination

Firearm fires are an infrequent occurrence, but bullet strikes from steel-core ammunition or
tracer and incendiary rounds can ignite dry fuels. There is usually evidence of firearm use near
the origin. Fire Cause Categories Firearms and ammunition:
An infrequent occurrence
Bullet strikes from steel core ammunition, tracer and incendiary rounds are common ignition
sources
• Evidence near the origin could include empty shell casings, target
materials, bullet holes or strike marks, empty shell boxes 5-20 First
Responder – Spontaneous Heating Most fires started from
spontaneous heating originate from inside chip or green slash piles.
Look for evidence of the pile at the origin and protect the area from
suppression efforts.
Fire Cause Categories
Spontaneous heating:
Most originate from inside chip or green slash piles
Evidence of the pile will be at the origin
• Do not suppress the origin area 5-21 First
Responder – Electric Fences
Electric fences occasionally start wildfires. Protect the origin, usually along the fence line, and
do not let the owner attempt to make repairs. Fire Cause Categories Electric fences:
Origin will be along the fence line
Protect the origin and the fence line itself
Do not let the owner make repairs
5-22 First Responder – Origin Identification
The most important tool you have in identifying the origin area of a wildfire is understanding
fire behavior. What you learned earlier in this program becomes very important in accomplishing one
of your primary responsibilities as a first responder – locating and securing the origin area.
Fire behavior:
Accurately identifying and protecting the general origin area of a wildland fire is one of your