On November 8, 2006, a 45 year-old owner of an electrical contracting company (the victim) died after falling approximately 9 feet to the road surface after the articulating boom of the aerial lift truck he was working from collapsed. The victim, working at a height of approximately 35 feet, was changing light bulbs on overhead streetlights along a state highway. After replacing a bulb, the victim began lowering the boom. The upper boom actuating chain connecting the upper and lower boom sections broke and the upper section fell, striking the truck bed and ejecting the victim from the bucket. The victim struck his head and neck on the truck bed before landing on the road surface. A co-worker (the victim's son), who witnessed the collapse from the ground, determined that the victim was unresponsive and began resuscitation efforts. A passing motorist called emergency medical service (EMS) personnel. The victim was transported to a local emergency department where he was pronounced dead. NIOSH investigators concluded that, to help prevent similar occurrences, employers should: 1. direct employees to immediately cease use of an aerial lift when it emits any unusual sounds, exhibits unusual motions, or fails to properly respond to controls; 2. strictly adhere to manufacturers' recommendations for maintenance and lubrication of aerial lift operating mechanisms; 3. ensure that qualified repair personnel conduct regular maintenance and inspections of aerial lifts; 4. maintain accurate records for boom maintenance and repair. Although the following recommendation does not apply to this specific incident, NIOSH concluded that as an additional measure of safety aerial lift operators should ensure that work crews using aerial lifts include at least one ground person with the ability to contact emergency assistance if needed.