A 57-year-old truck driver was killed when he fell from the top of a tanker truck while attempting to close the lid. The victim had been employed for three years with a trucking company that employed 2,200 workers nationwide. Approximately 500 employees worked at the California facility where the incident occurred. The scene of the accident was a cement plant designed with catwalks and weighted gangways that lowered to allow drivers to access the top of their tanker trailers for opening or closing the lid. Although the employer had a written safety program that included safe work procedures for closing the lid on tanker trailers, fall protection was not a requirement. Prior to the incident, the victim was working from a gangway that was extended over the top of his tanker. Although the gangway was outfitted with a guardrail, the victim slipped through a gap between the guardrail and top of the tanker trailer, falling approximately 12 feet to the ground. He was not wearing a fall protection device. A security guard discovered the victim after noting the tanker had been parked near the catwalk for an extended period of time. At that time, the victim was immobile and bleeding from the head. The security guard called 911 and the victim was transported to the hospital, where he was pronounced dead. Blunt head trauma was listed as the cause of death. To prevent future occurrences: 1. Ensure fall protection is worn by drivers who use catwalks and gangways to access the tops of tankers. Although the catwalk and gangway in this case were designed to provide fall protection to workers, a 24- to 36-inch gap existed between the tanker and guardrail, even when properly used. A personal fall protection device would have provided additional protection. The worker should have been equipped with an approved safety harness with a lifeline attached to an overhead anchorage. Lifelines should always be adjusted to ensure the employee cannot fall beyond a safe, specified distance. 2. Use a catwalk, gangway and guardrail system that eliminates gaps between the tanker and guardrail. Many manufacturers produce systems that provide access to the tops of tanker trucks. The system used in this case did not adjust to the height of various tankers. The incident might have been prevented if a system was in place that did not allow such a large gap between the guardrail and tanker truck.