Back about 8 years ago, there was this guy ( I liked to call him Jim Gymnasium) that was your typical toolbag bodybuilder wannabee...You know the type...He goes over to the cable crossover, and moves the pin to the bottom of one of the stacks.Instead of triceps pushdowns, I guess he's gonna do triceps extensions, where you grab the bar on the high pulley and face away from the machine, bending at the waist. Anyway, this clown thinks he's about to do the whole stack, but little does he know that he didn't shove the pin in all the way, so there is no resistance on the pulley.. He gives a twisting tug on the bar to get into position , thinking there is going to be resistance, but there is none...he ends up hurling himself, with all of his momentum, face first into the floor. He couldn't get his hands down fast enough to break his fall. He messed up his grill real good...blood everywhere...It couldn't have happened to a better guy!