Abstract: Employee # 1 and a coworker were installing 8 in. PVC lines at a shopping center that was under construction. The 16 ft deep trench was dug in soft, unstable soil. A trench box had been provided and employees had been instructed to stay inside the box because the trench walls above and beyond it were not adequately sloped for the type of soil. Employee #1 walked out of the trench box to spread gravel for placing the sewer lines. Both he and his coworker had done this several times with the knowledge of their supervisors. While he was spreading gravel, the walls of the trench collapsed and Employee #1 was knocked to the floor of the trench. He was covered with dirt but was able to breathe. Two vertebrae in his lower back were crushed, but a full recovery is expected.