I used to work with a guy that would go as hard as he could all day. He would frequently shoot himself with a staple gun. Then one day he was assembling a cabinet which a part was cut wrong he started to nail in so instead of having us replace the part he runs over to the table saw and proceeds to trim the part with a staple hanging down. When the staple reached the top of the saw it hung so he quickly reached over the back side of the blade to pick up the board. I heard the commotion and by the time I got to the front of the shop the foreman and shop owner was running him out the door to the hospital. Then I found out he had cut his thumb off. I asked the rest of them if they had taken the thumb with them and they said no so I went and found it and drove it to the hospital. You know sometimes they can re-attach a digit but the part of his thumb which was on his hand was torn up too bad to attempt it.
Then six to eight weeks later the guy comes back to work and they gave him a job which didn't involve power tools so they had him install drawers in cabinets. At the time we were using monorail slides and they didn't come in that many different sizes so odd dept cabinets the rail had to be cut with a hack saw. Within a couple of weeks the guy was going so fast he slipped with the hack saw and run the blade over the back of his hand cutting tendons off. This time he didn't come back.
This guy was really good at woodworking but he just couldn't slow down enough to be safe.