1. fall through, fall flat, founder, flop, fail, go wrong, miscarry
usage: fail utterly; collapse; "The project foundered"
2. founder, sink, settle, go down, go under
usage: sink below the surface
3. collapse, fall in, cave in, give, give way, break, founder, change
usage: 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"
4. founder, stumble, trip
usage: stumble and nearly fall; "the horses foundered"