Abstract: On April 27, 2009, Employee #1 was working with two coworkers digging three trenches at the front of a building to apply waterproofing materials to the exterior, below grade walls, surrounding an apartment. One trench was to the west of the main entrance and two were to the east of the main entrance. The trench to the west of the entrance was measured at approximately 35-ft by 5-ft by 6-ft at the east end, and 8 feet deep at the middle area of the trench. None of the employees were trained in trench safety, nor did they know how to install trench shoring. The two coworkers were working from west to east in the trench west of the entrance, installing hydraulic trench shoring from within the trench, without plywood at 6 to 8 feet deep. At the east part of the trench, Employee #1 was using a jack hammer to loosen soil to expose the wall under a patio, while another coworker was using a shovel to remove soil from the trench. At the patio edge of the building, a 15-ft section of concrete foundation was exposed. The employer did not provide support for the undermined section of foundation. The coworker saw that a section of concrete foundation, weighing over 1,000 lbs., at the edge of the patio was coming loose and yelled to warn Employee #1. As he was backing out of the area, the concrete foundation fell on Employee #1's upper back, suffocating and killing him.