Abstract: At approximately 10:45 a.m. on June 16, 1999, Employee #1, a general foreman, was supervising the installation of 4 in. thick, 8 ft by 12 ft metal shoring along the south wall of an excavation to hold back some loose rock until concrete could be poured. The operator of a Link Belt tractor backhoe was knocking down some protruding rock on the south wall approximately 20 ft away from the last section of installed shoring. The protruding rock was in the way of the shoring and had to be removed. Two 2.5 in. square by 45 ft long steel tubes, spaced approximately 46 in. apart as part of the shoring support system, were adjacent to the protruding rock. As the backhoe operator worked, his bucket uncovered a large 6 ft wide by 8 ft long by 3 ft deep rock. He lost control of it, and the rock fell down the face of the south wall and became wedged between the rock wall and one of the steel tubes. The weight of the rock first bent the steel tube and then snapped it in two. Employee #1 was killed when he was struck in the head by the end of the steel tube.