Abstract: Employee #1, an extruder operator, had about an hour left on his shift when the extruder machine that made dog food became plugged. He determined the machine was clogged where a screw conveyor delivered the dog food paste to the north dryer air lock underneath it. The air lock resembles a small turbine with fins or paddles that turn to measure out and pass along a specific amount of material. He passed the control panel and thought both the screw conveyor and the air lock were de-energized on the panel, so he opened the cover over the screw conveyor and reached in to clear out the material. The cover had an interlock that shut off the screw conveyor when the cover was removed. The screw conveyor did remain stopped, but as the dog food material was removed, the air lock began rotating again. Employee #1's right hand became caught between the air lock fins and housing, amputating his index finger just below the first knuckle and his middle finger at the first knuckle. Employee #1 was transported to McKay Dee Hospital in Ogden and kept overnight, but attempts to reattach his fingertips were not successful. Employee #1 had 21 years of experience and had been trained in lockout/tagout procedures. He was listed as one of the authorized personnel on the company's lockout/tagout program.