What type of structural collapse occurs when the floor and/or roof assemblies on both sides of a load-bearing wall collapse, allowing a good chance of victim survival?

The scenario described relates to a situation where structural elements on either side of a load-bearing wall give way, leading to a specific type of collapse. The A-frame collapse, characterized by roof structures that maintain their form but lead to a type of tilt or angular descent, creates void spaces that may increase the likelihood of survival for trapped individuals within the structure.

In an A-frame collapse, the integrity of the roof may remain partially intact, preventing total failure and thereby allowing for potential air pockets or spaces. This can provide a greater chance of survival for any individuals who might be trapped beneath the collapsed assembly, as the angles formed can create areas where they can be shielded from falling debris.

In contrast, other types of collapses, such as pancake and domino collapses, lead to a more complete and destructive level of failure, which typically results in less chance of survival due to the manner in which the structures fall and the lack of voids or protective areas. Understanding these collapse mechanisms is crucial for fire fighters and rescue personnel when they are assessing and responding to structural failures.