Long, unusual flame and heat damage at floor level is usually caused by what?

Long, unusual flames and heat damage at floor level often indicate the application of an ignitable liquid. When an ignitable liquid is introduced to a fire scenario, it can create a more intense and distinctive burn pattern compared to other ignition sources. This is primarily due to the liquid's ability to produce significant heat and flames, often leading to prolonged combustion at lower heights where it may pool or collect.

The phenomenon of seeing unusual flame patterns at the floor level can also be attributed to how the ignitable liquid behaves during combustion. It may vaporize, producing an extensive fire spread at lower levels that wouldn't typically occur with other sources. This marks a clear distinction in fire behavior that can be indicative of arson or intentional ignition rather than accidental causes.

In contrast, while electrical malfunctions, excessive heat from appliances, and unprotected heating sources may also cause fire damage, they typically do not present the same unique characteristics in flame behavior or damage patterns as ignitable liquids do. These other factors may result in damage higher up or a more erratic burn pattern that isn't concentrated at floor level as seen with ignitable liquids. Therefore, when assessing fire scenes for distinct burn patterns at this height, the application of ignitable liquids becomes a primary consideration.