Abstract: At approximately 2:00 p.m. on March 5, 1990, Employee #1 was repairing a damaged support strut that was located between the drive sprockets on the #4 bull chain conveyor. He failed to lock out the system before welding the damaged strut. At the same time, a millwright and the chipper operator were unclogging the conveyor to the sawdust bin. When the millwright sent the chipper operator down to the control panel to bump the sawdust conveyor, the operator accidentally hit the button next to the sawdust conveyor control, activating the #4 bull chain conveyor. The first time the button was pushed, the conveyor pulled Employee #1's left arm into the chain and sprocket drive to approximately one third of the rotation. Just seconds later, the button was pushed again, and the conveyor pulled his arm through the remainder of the rotation, severing his arm just below the shoulder. He was hospitalized for his injuries.