Which signs may indicate a building collapse risk during a fire?

• A. Water intrusion and cracking in the foundation are reliable collapse indicators.
• B. Visible sagging, bulging walls, creaking sounds, or doors that fail under pressure.
• C. A slight smoke odor in the hallway.
• D. The presence of a fire extinguisher on the wall.

Answer: (B)

Signs of imminent collapse during a fire come from clear, observable structural distress that shows the frame is failing under heat and load. Visible sagging or bulging walls, doors that won’t operate properly or fail under pressure, and audible cues like creaking or groaning from beams are direct indicators that the building’s structure is under severe stress and could give way soon. These signs mean the integrity of the frame is compromised, which is critical for deciding whether it’s safer to withdraw rather than to advance.

Water intrusion and cracks in the foundation can indicate existing problems or long-term damage, but they don’t reliably signal imminent collapse in the moment of a fire. A slight smoke odor is non-specific and common in many fire situations, and a fire extinguisher on the wall is standard equipment, not a marker of collapse risk.