Abstract: At approximately 9:20 a.m. on August 8, 2003, several employees were installing a metal stair rail the company had made. Employee #1 was preparing a stanchion that was installed into the concrete stairs to support the railing. Employee #1 needed power for his Makita angle grinder to prepare the pipe so that the railing would slide over the stanchion easily. A temporary power pole was installed on the site to provide power. Employee #1 found that the 110-volt outlets were being used, but there was a 220-volt outlet that was available. Employee #1 retrieved a 2-pole in to 3-pole adapter from the truck and found that he was able to jam the 110-volt adapter in to the 220-volt socket. After checking to see that the tool worked with the added voltage Employee #1 proceeded to grind the pipe. After approximately 30 seconds the wheel broke apart with the pieces of the wheel being shot out of the guard and a piece ricocheting off the metal pipe and hitting Employee #1 in the chest. Employee #1 suffered a puncture wound and was hospitalized.