What is the recommended first step in determining the area of origin during a fire investigation?

The recommended first step in determining the area of origin during a fire investigation is to examine the exterior of the structure. This initial exterior examination allows investigators to assess the overall condition of the building, identify any indicators of fire spread, and observe any signs of forced entry or areas that were particularly impacted by flames. By understanding how the fire may have traveled from the exterior, investigators can form hypotheses about the fire's origin and further direct their investigation.

Starting with the exterior provides crucial information that can help narrow down potential causes and identify points of vulnerability in the structure. It sets the stage for subsequent interior examinations and evidence collection. Furthermore, the exterior offers clues that may not be visible from inside, such as patterns of burn damage, points of ignition, and the presence of fuel sources.

This strategic approach can ultimately lead to more efficient investigations, as understanding the fire's behavior and origins from the exterior helps to focus investigative efforts and resources more effectively as they progress into the structure itself.