I think the worst crash I've "seen", since I don't get to get on snow a lot, is probably my own when i was like 9 or something.
I was still pretty new to skiing, as I had just learned it for the first time ever the season before. I decided to go down the Cut at Grouse instead of a bunny hill and I couldn't stop myself. I ended up straightlining/bombing all half way down the run at pretty damn incredible speeds. I only knew the "pizza" stop which obviously didn't suffice at such speeds and I ended up breaking the fence at the end of the run and tumbling over it. What's even worse was that I was super dizzy after I crashed and the people who "helped me" were just throwing me my yard saled-gear and laughing while doing it. I know it might've looked funny, the way I crashed, but it god damned hurt like a bitch. Plus my helmet was too big so it ended up bonking me in the head and then choking me while I was tumbling ):
and that's how I came back onto snow 3 years later and started snowboarding haha