Abstract: Employee #1 and a coworker were laying an 8 in. cast iron storm drain in an approximately 30 in. wide by 4 1/2 ft deep by 12 ft long trench. Employee #1 was in the trench, hand digging around underground electric wiring, when the trench caved in on top of him. He pelvis was broken in three places and he was hospitalized. The trench ran adjacent to a previously backfilled area or excavation where pipe had previously been installed. The trench was also subject to vibration from traffic on the highway that ran parallel to it, approximately 25 ft away. There was no shoring, sloping, or bracing in place to prevent a cave-in.