Abstract: Employees of Oak Contracting Company started the work day by carrying an electric saw and other related tools to the roof of a building. In an attempt to obtain electrical power for his tools, Employee #1 decided to drop a flexible cord through a 3 ft 6 in. by 5 in. roof opening that had been cut out to receive an air conditioning unit and that was nailed shut with a 4 ft by 8 ft 5/8 in. plywood panel. While trying to lift the plywood cover, the employee lost his balance, went through the opening, and fell 13 ft (1/4 in.) to a concrete surface. He sustained severe head fractures and was killed. Past job experience was the only safety training qualification required by the employer. When Employee #1 was hired two months before the accident, pre-employment safety and health training was limited.