I don't know about accident or incident, but I've had a self-inflicted stupid....

20mph, road tires, from pavement across a patch of deeper than expected sand... it ended badly. Didn't break anything, but torqued both shoulders and left hand and forearm badly during emergency, cement assisted deceleration. Pain lasted a couple months, took about six months to recover full function and strength.

Fortunately, no one that I know saw the event.

I'm also pretty good at slipping on wet pavement going too fast, but those are usually alot more funny and less damaging.