Abstract: Employees were constructing an interlocking retaining wall at the entrance to a construction site. The retaining wall was being built at the base of a 1/2:1 sloped excavation into a 32 ft high hill. Employee #1 and a coworker were working near the base of the hill when a section of earth slid down and trapped them. While a rescue effort was taking place, a second slide occurred, burying Employee #1 completely and burying two coworkers to their waists. Employee #1 died of asphyxia. All three coworkers were transported to the hospital for observation. The employees had not been properly trained in trenching or excavation safety.