When evaluating the spread of a fire, what should be assessed to deduce the direction of fire spread?

To deduce the direction of fire spread, assessing the depth of char is particularly valuable because it provides tangible evidence of how the fire progressed over time. The depth of char on surfaces indicates the duration and intensity of heat exposure at specific points. By examining areas with varying char depths, investigators can infer where the fire may have originated and how it traveled based on the uneven burning patterns.

While other factors such as the color of smoke can provide insight into combustion processes, and the size of the fire plume might suggest the intensity of the fire, they do not directly indicate the path of fire spread as clearly as char depth does. The type of fuel used can influence fire behavior but does not provide definitive clues regarding the specific direction in which the fire moved. Therefore, depth of char serves as a reliable indicator for determining the direction of fire spread in an investigation.