Abstract: Dirt had been excavated where underground duct work for an irrigation system was to be located. A road sign with a concrete base that weighed approximately 300 lb was adjacent to the trench. Employee #1 was instructed to enter the trench to clear dirt away from ducts. Employee #1 entered the trench and located the ducts. The foreman called to Employee #1 and told him to exit the trench and go to another area of the job site. No one saw Employee #1 exit the trench and he could not remember what happened but, probably, he grasped the sign to help pull himself from the trench because a ladder was not available. Employee #1 pulled the sign down onto himself. The road sign fell into the trench and struck Employee #1 in the right rib cage and pinned him to the ground. He required hospitalization.