Abstract: Employee #1, a laborer, stepped on a piece of plywood that was being used as a filler to span the 2 ft gap between the ends of two deck forms in a poured-in-place concreting job. The 19 ft wide by 60 ft long by 5 ft high deck forms were constructed of steel trusses and topped with plywood. When raised by jack screws, the decking reached a height of 9 ft 8 in. One of the deck forms was on rollers and was still being positioned, so the plywood between it and the other deck form had not been nailed in place. The other end of the filler had not been seated properly and was nearly hanging when Employee #1 stepped on it to bring materials to the deck form that was being rolled in. Employee #1 fell approximately 10 ft and sustained serious injuries.