Which pattern occurs when the flooring separates from exterior bearing walls but remains supported by interior partitions?

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

Answer: (D)

When exterior bearing walls detach from the floor but interior partitions stay in place to carry the load, the structure tends to form a triangular, A-shaped silhouette. The floor system is no longer tied to the outer walls, but the interior partitions continue to support the floor (and roof), creating two leaning “legs” with a cross brace formed by those interior elements. That visual matches an A-frame collapse.

This differs from a pancake collapse, where floors simply drop down in stacks, with little remaining frame intact to hold a triangular shape. It also isn’t a cantilever pattern, which shows one side staying supported while the other sags, nor a V-shaped collapse, where walls bow outward to form a V rather than an A.