When I was in 7th grade woodshop, a kid loaded a lathe with a 4" x 4" x ~18" piece of wood, and without checking, turned on the lathe at full speed. it flew off and a corner hit him exactly right between the eyes, splitting his safety glasses perfectly in half. (one half slid over right in front of where I was standing
). About 2 seconds later blood began to flow like I've never seen since. Because of the safety glasses, all he needed was a few stitches, but he had two very black eyes for quite a while.