I attended a man who had been building a garage. He had climbed the ladder onto the garage roof to nail shingles in place. The roof was about 9 feet high. As he stepped from the ladder onto the roof with his right foot, he stepped on some plastic that was on the roof. His foot slipped, and he fell feet first onto the ground. When he landed, he heard a loud crack. When we arrived with the ambulance, his leg was bent at 90 degree angle, 3 inches below his knee. It was a very nasty break.