Abstract: On July 24, 2009, Employee #1 parked his dump truck to pick up a load of material. He noticed a coworker, operating a front end loader, pick up a boulder and was getting ready to dump it into his truck bed. He was concerned about the load being too big for his truck so he yelled from inside his cab to back off, and blew his horn. The coworker did not respond to his commands, and Employee #1 walked to the loader where he knocked at the operator's door and yelled to back off. The coworker still did not respond and continued to proceed. Employee # 1 then climbed up on the top of the cab to see if his truck would be overloaded and the coworker dumped the boulder into the bed of his truck. The load landed so hard that it shook the truck, and Employee #1 fell off the truck cab roof onto the ground, approximately 9 ft. Employee #1 was hospitalized with a fractured back and a concussion.