Abstract: At approximately 12:30 p.m. on June 12, 2008, Employee #1 was pouring concrete to make stairs on the side of the house being remodeled. Employee #1 walked across the second floor of the house through the framing of the wall and stepped on a plywood sheet that collapsed. Employee #1 said he went through the framing and stood on the plywood surface to see if the concrete vibrator was plugged into a spider box located at a lower level. The joists, as well as other supports (concrete supports), were removed by the carpenters the morning of the accident due to the demolition project. The carpenters were going to renail the plywood onto new joists. The wood framing Employee #1 walked through did not have any openings 18 in. or wider, so it was not a wall opening that required a guardrail. Employee #1 was never told about the unsupported surface. However, the project manager of the general contractor said Employee #1 was told about the hazard before the injury. Employee #1 fell 9 ft to the ground when the unsupported surface collapsed. Employee #1 suffered a fractured left wrist, stretched tendons in his left hand, and a fractured and compressed L1 vertebra. Employee #1 was hospitalized for five days.