Abstract: At approximately 3:30 p.m. on May 3, 2000, Employee #1 and a track backhoe operator were installing a drain line for a new sewer system. The system was composed of 4 in. PVC pipes originating from the sewer distribution box and 6 ft long sections of plastic drain tile called "infiltrators." The workers were connecting the infiltrators by snapping the ends together, and lowering them into the trench. About six, approximately 14 ft wide by 68 ft long trenches had to be excavated for installation of the infiltrators. Before lunch, the workers had excavated one trench, installed the infiltrators, and backfilled it. After lunch, the backhoe operator excavated another trench approximately 5 ft south of the first one and placed the spoil pile on top of that area. The workers then assembled the infiltrators and installed them in the trench from east to west. When they were done, they noticed that the infiltrator at the west end had come apart. Employee #1 entered the trench at the east end and walked to the west end to reconnect the sections. As he was working, the northwest side of the trench wall caved in, trapping him at the bottom. Employee #1 was killed.