Three employees were on top of the asphalt grinder trying to troubleshoot why it wouldn't run. A fourth employee, a lowboy driver, walked over to the grinder unseen by the employees on top of the grinder. The employees started up the grinder. The lowboy driver's hand was caught in the moving belts on the back of the grinder. The employee suffered the amputation of the tip of his left middle and ring fingers, and had a pin surgically inserted in his left little finger. The employee was hospitalized.