cave in
n : the sudden collapse of something into a hollow beneath it
[syn: {subsidence}]
v : break 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" [syn: {collapse},
{fall in}, {give}, {give way}, {break}, {founder}]