(n)collapsea natural event caused by something suddenly falling down or caving in“the roof is in danger of collapse”, “the collapse of the old star under its own gravity”
(v)collapse, fall in, cave in, give, give way, break, founderbreak down, literally or metaphorically“The wall collapsed”, “The business collapsed”, “The dam broke”, “The roof collapsed”, “The wall gave in”, “The roof finally gave under the weight of the ice”