Which collapse pattern is created when a floor assembly collapses in the middle, producing two voids on either side?

• A. V shaped
• B. Cantilever
• C. Pancake collapse
• D. A-frame collapse

Answer: (A)

When a floor collapses in the middle, the center section drops away while the outer edges remain supported, causing the debris to pull outward toward the walls. This produces empty space on both sides of the center, so from above the pattern looks like a V with the apex at the midspan and two legs extending toward the sides. This V-shaped collapse provides clear cues to rescuers about where voids exist and where to focus search and shoring efforts.

Pancake collapse would show floors failing straight down into horizontal layers, cantilever collapse involves an overhanging portion that tips away on one side, and A-frame collapse forms a triangular, roof-like pattern.