Abstract: On June 24, 1993, Employee #1 and his coworkers were emptying a sand silo. The sand had about 5 percent water and was not flowing freely. Employee #1 shoveled sand from the silo's wall and climbed back up the ladder when the bottom filled up. He then signaled the third man on the ground to open the bottom gate. Employee #1 had done this same process three times that day. On this, the fourth time, however, he unknowingly worked his way down below the sand pile. He was standing at the bottom, at approximately 1:20 p.m., resting and wiping the sweat from his eyes and forehead when the pile of sand caved in and buried him. The standby on top of the silo went down immediately and cleared the sand off Employee #1's head. A fire department rescue crew pulled him to safety. Employee #1 then walked down from the silo uninjured. According to the supervisor, Employee #1 had been given a verbal instruction to stay at eye level and to never work below eye level or at the bottom of the sand pile. The employer had taken all the required precautions, and Employee #1 had received training and was experienced. No malfunction of equipment or procedures was found.