Abstract: Employee #1, a maintenance supervisor for Clougherty Packing Company, was called to inspect a prototype machine designed to split the carcass of a hog. The machine was designed to split the hogs in the middle and leave just enough neck bone to keep the hog in one piece. The machine was prevented from cutting the entire hog by an electronic sensor, which told a computer when to stop the machine. On the day of the accident, the machine had completely split two hogs. Upon examination, The maintenance supervisor found that one of the sensor's conductors was broken. He fixed the conductor and then tested the sensor with his bare hands to verify that it was functional. The sensor activated the starting mechanism of the machine, and the saw came down, fracturing and partially amputating the supervisor's thumb.