Abstract: At approximately 1:00 a.m. on September 25, 1991, Employee #1 was using an air hose to clean an Acme depalletizer conveyor, model 400-2D, located 18 ft above the concrete floor. He apparently was walking or crawling under an overhead light fixture when he tripped over the sweep bar of the depalletizer. He was found on the floor with severe head injuries and died on September 27, 1991. Causal factors include that guardrails were not provided on the open side of the conveyor and that the employee had not been instructed to wear a safety belt and properly tied-off lanyard. The conveyor has a metal mesh belt and is spongy to the step. There was good lighting and the area was dry. Employee #1 was working alone at the time of the accident.