Years ago I had a car roll off a set of ramps,while I was under it. I had a peice of 2X4 under the back wheels,certainly not big enough to block them. I knocked the tranny into neutral and the car slid down the ramps, the 2x4's kicking back slowly. I sucked in my belly,(it was smaller then anway) and moved with it, but not before taking most of the skin off my back, still have the scars. I often think if the wheels went over the 2by's, I sure wouldn't be here today!
Gary, thanks for ths reminder on this, Ithink we get to complacent at times.