Abstract: At approximately 11:48 a.m. on August 4, 2010, Employee #1 was in a trench helping fix a drilling head from a horizontal boring machine with a coworker. The project for this job location was to horizontal drill from the boring machine about 600 ft into a designated area, where a trench was dug. While horizontal drilling to the trench the drilling head broke. The crew then dug a trench to find the drill head. Once the drill head was uncovered they pushed it into the trench box to repair it. While Employee #1 and his coworker, were working in the trench box repairing the drilling head, they noted that one wall was shifting and sudenly, a section of the wall above the trench box caved in, striking and partially burying both of them. The coworker was able to pull himself out of the trench, suffering minor cuts and bruises. However, Employee #1, was struck in the chest and head by the collapsed wall and died of blunt force trauma in the trench.