Abstract: A 275 ft 4 in. PVC sewer line was being run from a house to a street tap in a trench that was 2 ft bucket wide and 8 ft deep in silty, sandy soil. One worker was above, handing down material, and another, the working owner/supervisor, was in charge. The second worker left to get supplies for the first 35 ft by 2 ft by 6 4 ft wide bench, which had been made on both sides. The next 100 ft by 2 ft bench was on one side, 5 ft down, but it was vertical. A vertical cleanout had been installed at 60 ft. Sometime between this and a second cleanout, the owner/supervisor returned and found that the second cleanout had been installed but was 15 ft short of the actual length. During the 1 to 1 1/2 hours while this was being done, Employee #1 ran a 1 in. copper water line alone to where the second cleanout had been relocated. A portion of the unbenched wall collapsed, striking him in the back with a rock and soil. Hand shovels were used to free his chest. When the soil was removed, he was carried out the end of the trench. Paramedics from a nearby firehouse took him to the hospital. A bulldozer had been grading on an adjacent lot that morning.