From Longman Dictionary of Contemporary Englishfall/collapse etc in a heapfall/collapse etc in a heapFALLto fall down and lie without moving They finally collapsed in a heap on the grass. → heap
Examples from the Corpus
fall/collapse etc in a heap• The foreigner stumbled on a few steps, his brains leaking out around his earphones, and collapsed in a heap.• Graham never saw what hit him, and collapsed in a heap on the floor.• Ace, Defries and Bernice fell in a heap.• Sure enough, the Mean Machine runs the same play again and Budanski collapses in a heap, not breathing.• The gallant commander and his horse fell in a heap... the horse dead, the rider unhurt.• The lion fell in a heap, and she got a steel knee on top of it.• Who knew when she might collapse in a heap of baubles and bangles? 