On August 13, 2005, a 56-year-old male construction worker (the victim) was fatally injured when he was run over by a bulldozer. While performing the role of a spotter, the victim apparently stepped in front of a pile of gravel to direct a truck driver to move his truck when he was struck by a bulldozer that was traveling in reverse. The company owner was operating the bulldozer in reverse, with its back up alarm sounding, and spreading gravel over the excavated area. A coworker, who was sitting in a skid-steer loader located near the gravel pile, saw the victim directing the truck driver and saw the bulldozer backing toward him. He yelled a warning to both the victim and the company owner. The company owner did not hear the warning and the victim did not react. The track of the bulldozer struck the victim on the back of his legs and rolled over his legs and torso. The company owner, still unaware of the run over, drove the bulldozer forward about 50 feet and stopped. The coworker ran to the bulldozer operator and told him what had occurred. The company owner looked back toward the gravel pile and saw the victim lying on the ground. He called 911 using his cell phone. He ran to the victim and began cardiopulmonary resuscitation (CPR). A police officer arrived approximately one minute after the 911 call and assisted in providing CPR. Emergency medical services (EMS) personnel arrived approximately two minutes after the 911 call and found, through examination and cardiac monitoring, that the victim had no signs of life. The county coroner pronounced the victim dead at the site. NIOSH investigators concluded that, to help prevent similar occurrences, employers should: 1. develop, implement, and enforce a policy that requires workers on foot to maintain a safe clearance from mobile equipment and train all workers regarding this policy; 2. develop, implement, and enforce a policy that requires mobile equipment operators to operate mobile equipment in accordance with safety guidance provided in the equipment operator's manual and provide additional training to all mobile equipment operators regarding this policy; 3. consider conducting a prework safety meeting each day to discuss the work to be performed, potential safety hazards and safe work procedures, and means to be used for communicating changes to the work plan; 4. ensure that personal protective equipment, including high-visibility clothing, is provided and used in accordance with company policy. Additionally, manufacturers of heavy equipment, such as bulldozers, should explore the possibility of incorporating collision avoidance technology on their equipment.