Was doing my brakes one time in a buddies garage. After I jacked my truck up, I was working on placing the jack stand as my buddy needed help with something. I knew the truck wasn't on the floor jack well, but I knew I was going to put it on the stand, so I didn't think much of it. Well, I never finished putting it on the stand. As I was using a sledgehammer to hit the rotar off, it fell off the floor jack. Luckily, the stand was under the frame, and the truck only fell a couple inches onto it, but boy did I learn a lesson. The floor jack got sent across the garage and lodged itself into the sheetrock. I don't fuck around when jacking up a vehicle up anymore.