Abstract: At approximately 2:00 p.m. on October 8, 1986, Employee #1 and two coworkers were installing ductwork in an elevator pressurization shaft on the 19th floor of an office building under construction. The shaft opening was 23 in. wide and approximately 16 ft long. Between the two ducts, workers were installing 10 in. by 10 in. metal plates on the wall. The duct work ended just below the 19th floor. The workers put a 2 by 12 board across the ducts to stand on while attaching the metal plates. They also had two 2 by 4s across the south duct. Apparently, Employee #1 jumped or fell down onto the 2 by 4s, which either broke or dislodged. He fell through the south duct and was killed. It was Employee #1's first day on the job. Safety belts were available but were not being used. The work platforms were inadequate and were not secured in place.