Replying to Worst crash/injury you've witnessed?

So what's the worst crash you've seen while skiing? And have you been the the first to arrive at the crash?
Some dos and don'ts for first aid on the mountain is accepted

Yesterday I saw a guy faceplant pretty bad on an icy stepdown, I picked up his skis and went to him when I noticed he hadn't moved for a while, then he started shaking around and doing that sound like when you suffer lung impact. Had to hold his head still until ski patrol arrived like 10 minutes later..