Which definition related to arson detection is incorrect?

The definition of "trailers" in the context of arson detection is that it refers to materials intentionally placed to help spread a fire, not simply the remnants left behind in the wake of a fire path. Typically, trailers are accelerants, such as gasoline or other flammable liquids, used by an arsonist to enhance the ignition or spread of fire to achieve their intended purpose.

The other definitions are accurate. An incendiary fire is indeed one that is intentionally set, which is a critical aspect of understanding arson. Combustibles are materials that can ignite easily under certain conditions, which is essential knowledge for assessing fire hazards and prevention methods. Flashover describes a critical moment in a fire development where all combustible materials ignite almost simultaneously, marking a significant and dangerous transition in a fire's behavior. Understanding these terms is fundamental for anyone involved in fire investigation and arson detection, as they help identify the characteristics and patterns of fire-related incidents.