An employee was polishing a feed screw with a handheld pneumatic grinder. The feed screw was in the grinding fixture. When he rotated the fixture, he noticed that the secondary safety pin fell out. He rotated the fixture to the vertical position and then applied upward pressure on the fixture arm. The 700-pound feed screw then fell out, knocking him to the ground and landing on his right leg and left hand. He suffered a broken and lacerated right foot, broken right ankle, broken right tibia, and lacerations to his left pinky and ring fingers that severed his tendons.