Wildland Fire Investigation, FI–210 Origin and Cause Determination

physical evidence you find. Do not allow any suppression activity to disturb the origin area.
Arrival at the Scene
First priority – Identify and secure the general origin area:
Use flagging or rope
Post guards as necessary
Keep suppression activity away
Keep all unauthorized persons out
5-38 First Responder – Identify Witnesses
Your next priority is to identify any witnesses in the area. Write down their personal and
vehicle information, and, if possible, have them wait for the investigator who will conduct a more
thorough interview. Write down the license number and description of any vehicles that drive by the
scene more than once, and take extra note of people who seem unusually interested in the fire, or who
try to assist with suppression or the investigation.
Arrival at the Scene
Next priority – Identify witnesses:
Have them wait for the investigator if possible
Obtain identification information -Name-Address
-Phone number
-Vehicle license number and description
5-39 First Responder – Record Data
Weather may be a critical factor in corroborating cause determination, so make sure to
properly record as much data as you can.
Do not touch any evidence unless it’s absolutely necessary to keep it from being destroyed. If
you have to move something, try and get a photograph of its original position first. Finally, make notes
on fire behavior at the time of your arrival and photograph the scene thoroughly.
Arrival At the Scene
Weather readings: -Take readings in an area consistent with origin conditions -Use a belt
weather kit or digital weather instrument -Record data for investigators
Physical evidence: -Tire impressions -Footwear impressions -Beverage containers -Any
obvious cause of ignition -Do not pick up or touch unless absolutely necessary to prevent destruction
General fire behavior conditions: -Wind direction -Wind Speed -Flame height and length -
Overall fire intensity -Direction of spread -Suppression tactics
Photograph the fire scene if possible
Identify vehicles that drive by origin area more than once