Abstract: Employee #1 and a coworker were preparing a roof so that roofers could cover it with new panels. Air conditioning units had been removed the previous May in preparation for a new roof and the roof box had been covered with plywood sheets and canvas so that rain would not enter the building. Employee #1 picked up a 4 by 8 sheet of plywood by himself and backed 6 feet into an opening, falling 14 ft 9 in. to a concrete floor. He sustained a fractured skull, toe, and ribs. If Employee #1 had waited for his coworker to help him lift the three sheets of plywood off the roof box, the accident would not have occurred.