Ok, I guess I should confess, my big crash. Years ago, at my old company I was doing something on a long pipe/tube. Like Steve300 said it went right through the through hole and stuck out about 5 feet. I was busy cutting the end by the chuck. I guess the speed was to fast and the 5 feet sticking out had to much centrifugal force on it. It folded over. Now it was a swinging pipe. I was on the safe side of the chuck, but there was a giant tool box that held all the tooling for the lathe and mill on the other side. Of course it got beat to shit and sent stuff all over the shop. It made so much racket, we had neighbors from down the street come and check on us. I took a lot of ribbing over that one. Both of my business partners were ticketed machinists. They put up sign saying “no pilots on machines”.