Abstract: Employees #1 and #2 and a coworker were hand digging a footing for a new retaining wall of a single-story home at a construction site. The old retaining wall had been damaged in an earthquake, and they had knocked it down to grade. The wall extended approximately two more feet more below the surface. They decided that they would leave the old section of retaining wall and put in a new retaining wall approximately 1 ft away from the old one. Employees #1 and #2 had dug down approximately 5 to 6 ft when the old block wall became undermined. While they were still in the excavation, the 88 ft long old retaining wall and the dirt around it caved in because of their weight, trapping the two workers. Employee #1 suffered a broken left wrist and Employee #2 sustained a possible broken leg. They were rescued by the fire department and transported Holy Cross Hospital.