Abstract: On March 30, 2011, Employee #1 and a coworker were laying concrete. Employee #1 was attempting to loosen the cement mixture within the pumper hose as the coworker was holding the end of the hose and directing the cement within the forms. The cement mixture stopped flowing for an unknown reason. The coworker alerted the cement pumper truck operator, which motioned back to the coworker that he did not know why the cement had stopped flowing. The coworker watched the cement truck operator walk to the back of the pumper truck where the hopper and a cement truck were located. The cement truck operator shook the cement trucks chute to encourage the cement to flow down into the hopper. There was an explosive sound a couple seconds later. As the explosion sounded, the end of the pumper hose flipped around violently, striking Employee #1 and the coworker. Both employees sustained unspecified injuries. They were transported to a medical center, where Employee #1 was hospitalized and the coworker was treated and released.