I've had a couple of mine fall onto cement
from my lap and/or the patio table - probably more like landed wrong as I believe they were jumping off, not falling. Either way, THANKFULLY, they were scared (me even more so; it sounded awful!), but fine.
It is scary, these little ones. Even on the ground, they run soooooo fast. I'll see them running like crazy after each other outside (or in) and I fear they will end up running into something head first, or even run into each other. Or, with all the hardwood floors in my house, I fear throwing a toy for them to chase in case they should run fast, slide, and not be able to stop before sliding into a door or furniture. Geesh, gotta watch them and protect them just like kids.........