Had a buddy who did this in high school. He was breaking in a new cam in his mustang which was up on stands. I guess the car started to rock a little and him liking the sound of open headers got the best of him the car fell off the stands. The only thing was when it landed on the jack stand were guessing it hit the linkage underneath the car. It layed about 30 feet of rubber and went right through the back of the garage, across the lawn , through the hedge into the neighbors yard where it stopped in his garden.
Funniest thing I have ever seen.
Glad no one was hurt. Just a very bruised ego and the fact he had to rebuild the car, the garage, and replant a new hedge. Old man next door hated him anyway so no biggy about the garden. LOL