Abstract: At 6:15 p.m. on July 11, 2017, Employee #1, Coworker #1, and other coworkers, employed by an excavation company, were working at the site of a trench excavation. They were installing a sewer pipe in the trench, which measured approximately 7 feet deep by 3 feet wide by 40 feet long. A partial collapse occurred on the trench's northern wall. The workers removed the trench shield, and Coworker #1, operating an excavator, began cleaning out the collapsed soil. Employee #1 moved onto a graded hillside near the northern wall to observe the clean-out work. As he walked along the trench edge, a second collapse of the trench wall occurred. Employee #1 fell into the trench, and a large piece of shale rock within the collapsing soil pinned his legs just below the knees. Emergency services were called, and Employee #1 was transported to the hospital. He was admitted and treated for fractures to both legs.