Abstract: Employee #1 and two coworkers were working on core walls of an elevator shaft area. Employee #1 had tied about nine bars together inside a wall form that was located above a floor opening. He then climbed onto a wooden guardrail that had been secured to the wall form using 16-gauge wire. The top rail let go and Employee #1 fell onto the metal beam support in the floor opening. He was suspended about 12 feet above the subway floor and, if not suspended, would have fallen 18 to 19 feet to the subway floor. Employee #1 suffered two or three fractured ribs, a punctured lung, and a puncture wound to his left side when he struck against four sharp-edged irons on the metal beam support. He was hospitalized.