Abstract: Employee #1 and a coworker moved a rolling tower single point scaffold from one roof to an adjacent roof to use while washing windows. They set up the scaffold and attached three 55 lb counterweights to the rear of it, without tiebacks. They then proceeded to attach a boatswain's chair to the hook of the beam scaffold and a lifeline to the same hook. Employee #1 fitted himself with a body harness, attached the lifeline to the harness, and got into the boatswain's chair. He went over the side of building and proceeded to wash the exterior windows. When he finished one window, the coworker would move the rolling scaffold to an adjacent window and Employee #1 would clean it. When the coworker looked over the side of the building, the rolling scaffold upended and catapulted over the edge of the building. The scaffold and Employee #1 fell 72 feet to the adjacent concrete level; he was killed. The employees had elected to use #9 wire to attach the counterweights to the rear of the rolling scaffold. The wire broke, allowing the weights to fall to the roof.