It happens. I once did a similar move as the OP here and whacked my hand against the neck board of a monochrome VGA monitor, cracking off the pip while trying to unplug something. Several years later I was working on a nice 15" SVGA back when that was considered quite a nice monitor and I left something unplugged, causing the beam to not blank instantly when I shut the monitor off and it instantly burned a little dot into the center of the tube. Several years after that I knocked something over in the garage and it fell just perfectly and smashed the neck off an arcade game monitor that I was repairing for someone else. Doh! That one was in great shape with no burn either CRTs are fragile. At least the larger ones usually have a protective cap over the exhaust pip.