Abstract: Employee #1 was operating a bridge breaker machine (now called an arch master) at an Agway feed mill. This mobile unit is placed over a bin opening into which a rotating auger is lowered to break up the jammed feed grain so that it would flow out the bottom by gravity. Employee #1 was working on 54 ft deep bins and he was drilling up to three holes in each to loosen the feed. He attached 4 ft sections to the auger head until the tip of the drill reached the grain. Using control levers at the motor, he was able to raise and lower the auger and reverse its rotation to facilitate breaking up the feed grain. Employee #1 was trying to raise the auger out of a bin and was reversing its rotation repeatedly to get it out of the hole. When he saw that this was not working, he grabbed the auger and pushed on it so that it would free itself from the feed. He continued to do this, stopping the auger periodically to remove sections of it as it slowly inched its way up. Employee #1 was preparing to remove the next section and was shaking the auger to help free it when his work glove became caught on the slowly rotating unit. It twisted him around so that he was unable to reach the controls to shut it off. The auger continued to twist around until his arm was torn off. Employee #1 left his arm wrapped around the auger while he walked down five flights of stairs to the office and yelled for help. He then asked some coworkers to go upstairs and retrieve his arm. Subsequent attempts to surgically reattach his arm were unsuccessful. Although shaking the auger is not supposed to be a requirement for operating the equipment, the operator is required to be in very close proximity to the rotating parts to assess the progress of the drill and to determine the proper positioning and appropriate rotation of the auger. In addition to the unguarded rotating auger and supporting structure, the bolt used to secure the auger sections was unguarded and projecting. The manufacturer recognized the hazards of this equipment and included cautionary warnings on the first page of the Instruction Manual, under the heading of Safety Rules and Precautions. Employee #1 was operating this equipment by himself. During the investigation, management stated that operating the equipment was a two-person job. Some coworkers indicated that there had been times when they were told to operate it on their own. Page 6 of the Instruction Manual states that for maximum safety and efficiency, the arch master (bridge breaker) should have two operators. It was noted that the Manual used the term "should" rather than "must" or "shall".