fallShe slipped and fell.
dropSeveral apples dropped from the tree.
collapseSeveral buildings collapsed in the earthquake.
crumpleHe fainted and crumpled into a heap on the floor.
tumbleA huge rock tumbled down the mountain.
plungeFour of the mountaineers plunged to their deaths when their ropes broke.
plummetThe car went out of control and plummeted over the cliff.
tripShe tripped over a crack in the pavement and broke her wrist.