Abstract: Employee #1 and a coworker, both plumbers, were installing a 6 in. return hot water line inside an elevator shaft opening, starting at the sixth floor of the building. They were working from a platform composed of four 2 by 16 planks resting on beams, with the ends of the planks extending past the beams by approximately 4 1/2 ft. They had finished installing 20 ft of the pipe and, in preparation for moving their materials to the next floor, removed the guardrails on the south side of the work platform. Employee #1 was picking up the first plank when he stepped back on the overhanging section of the third plank. It flipped off the beams and Employee #1 fell 66 ft to the basement. He was killed.