Abstract: Employee #1 was standing in a 4 ft deep trench after pipes had been laid and then covered with sand in preparation for back filling. The aluminum hydraulic shoring was removed, and back filling began when Employee #1 signaled the operator of the Case 580K backhoe while still standing in the trench. As a coworker pulled the last jack of the aluminum hydraulic shoring, he instructed the operator of a Case 580K backhoe to go to the other side of the trench to begin back filling. The operator shouted at Employee #1 just as the trench wall collapsed on him. An 18 in. wide by 12 in. thick by 10 in. long piece of saw-cut cement fell from the west side of the trench, pinning Employee #1. Coworkers used tools and an aluminum shoring jack to extract him. Employee #1 sustained low back strain and other minor injuries, and was hospitalized for 48 hours. The employer was cited for accident-related violations of T8CCR 1541(i)(3) and T8CCR 1541.1(e)(1)(b).