Not nice, at all.
Thi is one of the things I don't like about bikes. Zero protection if it all goes horribly wrong.
Coming off my mountain bike at about 30 mph when the chain snapped going downhill on the main road leading into Llanwertwyd Wells back in '87 still makes me shiver and shudder to this day, remembering that dreadful feeling of being totally 100% out of control as the road rushed up to me.
I won't go on about the consequences of the fall, but its affected my entire life ever since.