My biggest fear in skiing is the "other guy". A 200+lb missile hurtling down the slope in a possibly uncontrolled manner. I have had many near misses. I also can't believe how many people still don't wear helmets (not that they are infallible)
On the plus side, I have just finished my 10+th (have lost count) year of running my school's ski club. Sometimes up to 40 kids. No serious injuries since I've been the coordinator (not that I have any control over that).