Abstract: On February 26, 2002, Employee #1, a plasterer, was working on the roof above the kitchen of the single-family residence under construction. The employee was installing wire mesh to the wall on the part of the house that is two stories high. As the employee stepped on a skylight opening plywood cover, it became displaced and he fell about 13 feet to the concrete floor. Employee #1 was hospitalized with fractures of the facial bones, both wrists (compound), pelvis, and ribs. The investigation revealed that the construction manager asked the framing contractor to cover the skylight opening about two weeks earlier when he became concerned about rain. The framing contractor placed a plywood cover over the hole but did not secure it adequately enough for someone to stand or step on. In addition, someone covered the plywood with black waterproof paper with only a third of the plywood showing. The next day another official of the framer saw the plywood cover and wrote a 'Do Not Step' sign on the exposed portion of the plywood, but it was hardly visible. Employee #1 reported that he saw the piece of plywood sticking out from under the waterproof paper but thought it was just scrap lumber.