Lets put this in prospective. You park your car in the normal parking lot and the beaten path to miles and miles of ice.... as far as you can see... has a pressure crack in it that someone has thrown a plank/pallet etc across to make walking easier. No big deal..... and off you go until a perfectly directed wind takes one end of that 5+ miles of ice and starts swinging it out opening the gap, while you are unaware fishing on 2 feet thick ice.... 'till someone decides to leave or get on ! Many sledders apparently drove off at the other end.