Cars falling off supports used to happen with a fair regularity. Some people even survived. Hopefully it occurs far less today.

It probably does just because fewer work on their own cars now than for many previous decades.

I have never really feared almost anything. Still getting underneath a car not really supported so it just could not drop on you was always beyond my fear threshhold.

I do not even trust jackstands. I know that is a little irrational yet I cannot help it. The car always had to be solidly blocked up in a way that satisfied me.

Also if you use a set of drive up on ramps to change oil or whatever. The cheap ones can collapse. I have seen it happen. Get a block of wood that just fits inside them if not certain of their strength. Or properly weld additional support to them. These old mercedes diesels are heavy on their front ends.