Abstract: At approximately 10:00 a.m. on August 12, 1999, a maintenance worker was attempting to retrieve a loose bolt from inside a rotary waste screen. He drained the water in the waste screen reservoir so that the float would be below the preset mark thus stopping the rotary screen from rotating. He then reached into the opened end of the stopped screen to retrieve the bolt. While he had his arm inside the tumbler, the screen activated and started turning. His arm was pinned against a cross brace member of the tumbler. He screamed for help. Coworkers working in close vicinity of the rotary waste screen heard the pleas for help and ran to render assistance. The employee suffered serious bone fractures on his right arm and was hospitalized.