[tdw28210]

Unless the car somehow bounced off the arms (unlikely as we are talking 3 inches between locks) there there is a good chance that lift was gerry-rigged somehow. They don't crash to the floor when a cable snaps.

Anyway, check the floor bolts and make sure the cables aren't twisting and fraying. On my 4 post, if I let them get too slack when resting on the locks, they twist. I also run Caterpillar fluid conditioner in mine too.