Abstract: Employee #1, a full time Operator/Inspector saw a piece of material on a material return conveyor belt and thought that it was crooked and might stop the line. According to Employee #1, she had done cleaning in the machine after maintenance locked it out, but she never locked machines out herself. Employee #1 did not tell any coworkers of her intent to enter the machine. The machine was left running. Employee #1 went to the rear of the machine and entered through an unguarded 12 in.-wide by 44-in.-high opening. It is 10 in. to the edge of the lift track and 36 in. to the end of the conveyor. Employee #1 knelt down on one knee and leaned into the area under the material lift. As Employee #1 reached to straighten the material on the conveyor, the material lift came down on her, crushing and pinning her, then lifted off her. A pneumatic piston operates the material lift. The piston had apparently reached the limit and lifted off her. Employee #1 was hospitalized for her injuries.