<p> Fire Investigator Chapter 24: Wildfire Investigations Ready for Review</p><p> Wildland fire investigations are used to determine the origin and cause of a fire and responsible party of wildfires.  Investigators must learn to read the indicators that the wildland fire impresses on the landscape to determine where the fire started.  Investigators must preserve the origin and all evidence correctly, conduct interviews, and prepare professional investigation reports to prepare for cost recovery, where applicable.  Fuels are classified as ground fuels, which include all flammable materials lying on or immediately above the ground or in the ground, and aerial fuels, which include all green and dead materials located in the upper forest canopy.  Wind speed and wind direction are important factors to consider when determining the possible area of fire origin.  In identifying the area of origin, considering the factors of wind, topography, and fuels. The origin is normally located close to the heel or rear of the fire.  By back tracking the progress of the fire, the investigator can retrace the path of the fire to the point of origin.  Potential causes of wildfires include the following:  Natural causes  Human causes</p>