Abstract: On November 17, 1999, Employee #1 and another employee were installing a trough system in the interior of the water treatment containment. The containment was constructed of concrete and formed in the shape of a large cylinder. The trough system was constructed of steel and rested on 5.75 ft steel supports above the bottom interior surface of the containment. The steel supports were mounted to the surface of the concrete containment with 6 in. bolts and epoxy adhesive. The trough system was designed to transport the flow of water to the containment. The employees were in the process of placing the trough onto the supports, and tack weld an uneven section of trough to a neighboring section of trough. It was standard procedure for an employee to stand on a trough section which was uneven in order to level it with the neighboring trough system, while another employee tack welded the two troughs systems together. This procedure exposed Employee #1 to a fall of 5.75 ft. The employer had written fall protection policy that requires employees to be tied off when working at a level of 6 ft or higher. As Employee #1 stood upon the uneven trough, a top bolt to a steel support loosened and pulled out allowing another section of the trough to fall. The steel support that fell was roughly 20 ft away from where he was standing. The trough did not completely sever from all of its supports because the employer had secured the trough with brackets in order to prevent this from occurring. However, the fall of the far end of the trough system (which was the system they were attempting to level) causing the rest of the trough system to twist. This twisting action knocked Employee #1 off from where he was positioned. He fell 5.75 ft onto the concrete below striking his head on its surface. The force of the impact on his cerebrum caused hemorrhaging, which was not fatal. He was hospitalized for hematoma (the collection of blood resulting from hemorrhaging) and received surgical and postoperative treatment.