The lean to, V shape, A- Frame, pancake and cantilever are all types of _____ patterns.

• A. Collapse
• B. Collapse patterns
• C. Patterns
• D. Cribbing

Answer: (B)

Recognizing collapse patterns means understanding the geometric shapes the debris forms as a structure fails. Lean-to, V shape, A-frame, pancake, and cantilever describe how the collapse looks in the rubble—how walls and floors tilt, bow, or drop to create distinct profiles. These terms are used because they convey the specific failure geometry responders will observe on the scene, which helps in locating voids, predicting movement, and planning stabilization.

Lean-to pattern shows one side collapsing, leaving a sloped, triangular line. A V pattern forms when two sides give way toward the center, creating a V from top to bottom. An A-frame resembles an inverted V or an A-shaped profile, with members leaning toward each other. Pancake collapse refers to floors or slabs dropping more or less flat, stacked like a stack of pancakes. Cantilever pattern occurs when part of the structure fails while the other end remains anchored, causing an outward projection.

So these are all examples of collapse patterns—the observed configurations of a structure after failure. The other terms don’t fit because cribbing is a stabilization technique, and collapse or patterns alone don’t specify the particular geometric configurations seen in a collapse.