This actually happens a lot more often than people realize.
Nascar driver Steve Parks' careeer was ended when his sterring wheel came off during the pace laps before the start of an oval race.
Oval track cars are set up to tun left, all the time. Drivers actually have to steer to the right to get the car to go straight.
So when his steering wheel came off, his car took a hard left. Unfortunately, Larry Foyt was down on the apron heading for the pits at a speed much faster than the field and Parks' car turned left right in front of Foyt. Foyt t-boned Parks right in the drivers door and Parks was seriously injured.
Denny Hamlin's steering wheel came off at one of the oval tracks this last season too, but he managed to get the car stopped in the in-field without hitting anything.