I had a very large bottle bomb. While fermenting, the blow-off tube in the glass carboy became clogged overnight and the carboy exploded. It was a HUGE explosion and there were pieces of carboy stuck into the ceiling and walls of the kitchen (where it was fermenting) as well as the two adjoining rooms. Luckily it happened in the middle of the night, so nobody was awake. If anyone had been standing in the kitchen when it exploded, my guess is that they'd be swiss cheese.
This is the reason I stopped brewing for many years, and why I avoid using glass carboys now.
I have 2 65L laboratory-grade Nalgene carboys that I use as primary fermentors. Even when the fermentations go nuts and the krausen is really rocking, I haven't had to ever use a blowoff tube. I use glass carboys exclusively for secondary.