Abstract: At approximately 8:47 p.m., on September 14, 2005, Employee #1 of an industrial cleaning company and often does contract work in refineries. In this particular contract, employer was given the task of cleaning waste tanks. Employees #1 through #3 were on the night shift on the night of the accident. After the tanks had been emptied of water, the employees descended into the tanks one by one to manually pick up solid debris. The actual worksite is an area which had several tanks or pits. The pits were of different configurations: there were rectangular, square as well as round pits, varying in depth from 15 to 30 ft. While the pits were separated by concrete walls, they were connected together at the bottom but were guarded by gates. After coming out of a 15 ft pit, Employee #1 was resting on the perimeter of the pits, preparing to enter into a 30 ft pit. He was wearing a body harness with a lanyard. Employee #1 was a six foot tripod, an emergency rescue equipment, leaning against a post. Upon seeing that his coworkers were having difficulty setting up a ladder for the next descend, Employee #1 walked across the top of the walls of the pits to help Employee #2 and Employee #3 out. As he walked across, employee #1, somehow pulled the tripod with him, the tripod fell and dropped into one of the pits, pulling him down with it. Before Employee #1 fell into the hole, his head hit the lip of the 29-in. wide pit, causing him to die of blunt head trauma. It is not clear whether his landyard got entangled with the tripod or that Employee #1 had hooked both his lanyard caribeeners into the tripod. According to refinery management, when the tripod was retrieved out of the pit, both caribeeners of the lanyard of Employee #1 were found hooked up to the tripod.