Abstract: On September 24, 2007, Employee #1 and two coworkers were engaged in installing water pumps and piping at a pump station. In this process, it was necessary to vertically join together 10 ft long assemblies consisting of three parts. The innermost part was a metal water pipe with an approximately 20 in. diameter. These assemblies weighed several hundred pounds and were handled using an overhead hoist operated electrically by an operator with a direct line of sight to the assembly crew. The stainless steel axle, when fully assembled is driven by an overhead motor and is used to activate an impeller that drives water vertically up the water pipe. The 7 in. metal axle housing protects the axle and weighs approximately 200 lb per 10 ft section. The outermost water pipe carries water upward to large pumps for transportation through larger water lines. It has collars welded inside it just large enough to allow the axle housing to be held firmly in place when installed. At the time of the accident, the stainless steel axle had been lowered and connected to the axle section below it. The operator was lowering the axle housing to be threaded into the coupling on the housing section below it when the axle housing section became caught on a collar inside the outermost water pipe. This resulted in some slack in the hoist chain that was not visible inside the water pipe. Not seeing the next section of the axle housing, Employee #1 put his hand into the water pipe to locate the axle housing, thinking it was secured by the hoist. At that instant, the axle housing slid through the water pipe collar, catching Employee #1's thumb between the edge of the falling axle housing and the axle housing coupling below. His thumb was partially amputated and he was transported to the hospital for treatment.