Abstract: At approximately 10:00 a.m. on May 15, 2007, Employee #1, a traffic signal technician, was repairing a pedestrian signal box that was approximately 6 to 7 feet above the ground. He was working alone and was found by a passerby in the street in front of his work truck. He suffered blunt force trauma to the back of his head and was going in and out of consciousness. He was transported by emergency services to Stanford Hospital where he was hospitalized. He was then transferred to a rehabilitation center that specializes in brain injuries. There were no eye witnesses to the accident. Further investigation revealed that the employee had been working at the street level and was using a chain wrench and a 2-inch-diameter piece of rigid pipe as breaker bar to adjust the signal framework. It is believed that the most likely cause of the accident was that the employee was using the breaker bar on the chain wrench, trying to get leverage, when he slipped or lost his balance and fell backward off the curb and hit his head on the street. There was a portable lift bucket attached to the employee's work truck and the bucket was located approximately 8 to 10 inches off of the sidewalk. However, it did not appear that the victim was in the lift when the accident occurred.