Abstract: At 9:23 a.m. on September 22, 1999, Employee #1, the foreman, and three coworkers were installing a new parabolic dish at the 60-ft level of a microwave tower. This was a very experienced crew with over 20 years of combined experience with the same employer. Two coworkers were groundmen in charge of sending materials and tools to the two-man crew working on the tower by means of a block and pulley system powered by a portable capstan hoist. Employee #1 had held a pre-job meeting and discussed how he wanted the job to proceed. He and a coworker then climbed the tower and belted in at the original planned point of attachment. He then told the other towerman that he had changed his mind, that if they placed the mounting hardware slightly higher than previously planned they could take advantage of existing predrilled holes in the tower, making the installation easier. The coworker agreed and communicated to the ground crew what materials and tools they would need to have sent up. He then positioned himself to guide the tools and materials around obstructions as they were hoisted up the tower. Meanwhile, Employee #1 set about detaching a 2 5/16-in. by 20 in. galvanized angle iron brace that had to be removed to accommodate the new plan. In the process of removing the bolts, Employee #1 encountered difficulty. The bolt and nut wanted to turn, requiring him to use a backup wrench to get the nut off the bolt. He became preoccupied with removing the nut from the bolt and was using a deep well ratchet socket to remove the nut, which hid the threads of the bolt from view. When the nut finally came off the end of the bolt, the end of the angle iron came loose from the tower and the positioning hook of his safety harness slid off the end of the angle iron. He fell 60 ft and was killed. Employee #1 had forgotten or did not realize that his safety harness was tied to the same angle iron that he was removing. He had also failed to secure a second safety line to a separate contact point.