Which hazard is of particular concern with fires involving stacked or piled material?

• A. Collapse of the stack
• B. Rekindle
• C. Toxic exposure
• D. Interference with sprinkler systems

Answer: (A)

When fires involve stacked or piled material, the main risk is the stability of the pile itself. Heat weakens the structural supports and bindings within the stack, and the weight above can cause a sudden, violent collapse. A falling, burning pile can trap firefighters and occupants, push flames and embers into new areas, and rapidly change the fire’s direction and intensity. While rekindle, toxic exposure, and sprinkler interference are important fire hazards in general, they’re not as specific or primary to stacked materials as the potential for a destructive collapse of the pile.