In a construction project, a company built and 18-foot-by-20-foot trench that had to be lined with a special fabric. When the workers had trouble stretching the fabric over the trench, an employee volunteered to go into the trench and fix the problem. His supervisor stopped him, saying it was too dangerous because the walls of the trench had not been properly supported. After several additional failed attempts to stretch the fabric, the supervisor relented and told the employee to go into the trench. Within five minutes, he was seriously injured when the trench collapsed.