Which collapse classification corresponds to ordinary construction collapse with potential entrapment by load-bearing members and risk of secondary collapse?

• A. Basic
• B. Light
• C. Heavy
• D. Moderate

Answer: (D)

In collapse classifications, the level reflects the hazard risk to trapped victims and the likelihood of further, uncontrolled failure. When the collapse is in ordinary construction and there is a real danger that entrapment could involve load-bearing members, with a genuine threat of secondary collapse, the scenario sits at a moderate level. It’s more hazardous than a basic or light collapse, which imply minimal risk and fewer structural hazards, but it isn’t at the extreme end where the structure is failing so dramatically that entry and stabilization become greatly more dangerous. The presence of entrapment risk from load-bearing members and the potential for additional collapse are the hallmarks that push this into the moderate category, guiding responders to emphasize controlled stabilization, careful shoring, and deliberate search-and-rescue operations rather than aggressive entry or rapid, unconstrained intervention.