Abstract: Employee #1 and coworkers were replacing a worn mantle in a primary screen and crushing unit for copper slag. Mild steel lifting eyes had been welded onto a new manganese mantle, which weighed approximately 1,700 lb. The employees used a wire rope sling and a mobile crane to lift the mantle off the ground. Employee #1 went under the suspended mantle to clean the seal before installing it in the crushing unit. He had been under the mantle for approximately three minutes when the weld on one of the lifting eyes failed, dropping the mantle onto him. Employee #1 was hospitalized with a fractured back.