How does NFPA® 921 describe fire patterns?

NFPA® 921 describes fire patterns as visible and measurable physical effects remaining after a fire. This definition emphasizes that fire patterns are the result of the interaction between the fire and the materials in the environment, which leave behind distinctive marks or evidence after the flames have been extinguished. These patterns can provide crucial information about the fire's origin, intensity, and the involvement of possible accelerants, ultimately assisting investigators in understanding the circumstances surrounding the event.

The focus on visibility and measurability is important, as it indicates that these patterns are not merely subjective impressions, but rather objective physical evidence that can be analyzed. This assists in accurate fire investigations, ensuring a more scientific approach to determining what transpired during the incident.