What hazard is particularly concerning with fires involving stacked or piled material?

The concern with fires involving stacked or piled material primarily stems from the risk of collapse. When materials are stacked or piled, they may not have a stable base, and the integrity of the stack can be compromised by the heat of a fire. As the fire burns through the materials, structural stability can decrease, leading to the potential for a partial or complete collapse.

This is particularly dangerous for firefighters because a sudden collapse can occur without warning, posing significant risks to their safety. The weight of the materials, combined with the changes caused by the heat and the fire's impact, creates an unstable environment. Therefore, it's critical for firefighters to assess the stability of such stacks and implement appropriate safety measures before engaging in firefighting efforts or rescue operations in their vicinity.