Abstract: Employee #1, of Sun World, Bakersfield, CA, was helping a plumbing contractor install a 30 in. diameter infiltrator system. The high capacity, sidewinder leach line was in a 105 ft long by 3 ft wide by 6 to 11 ft deep trench to the west of some employee housing at Ranch #75. Employee #1 was in the northern end of the trench, standing atop the installed line, while the contractor was standing on the bottom of the trench, even further to the north. The side of the trench caved in, and loose dirt and a piece of asphalt trapped Employee # 1 at mid-thigh level. The contractor was completely covered and was killed.