Man, it kills me to even think about this...
I was just about to start a gig in Philly. The bass was on a guitar stand, not plugged in, and nobody was within 10 feet of it. Somehow, it fell off the stand and hit the stage face-first. I heard a crash, looked over my right shoulder, and saw that the headstock had snapped off completely. I haven't had a bass in a guitar stand since.