A diver harvesting sea urchins died as a result of breathing air contaminated with carbon monoxide. Two divers were using scuba gear in about 40 feet of water; their air tanks were refilled by the divers' tender aboard the fishing vessel. One diver resurfaced shortly after starting his third tank because he thought he was having a heart attack. When breathing fresh air made him feel better, he realized that the air in the tanks must have been contaminated. A search was carried out for the second diver who was found a few minutes later, unconscious on the ocean floor. He could not be revived.

On the day of the accident, the unsecured high-pressure dive compressor on the vessel's deck had shifted, and the exhaust pipe melted a hole in the plastic air intake hose. High levels of carbon monoxide from the exhaust of the compressor's gas engine contaminated the air used to refill the dive tanks.

Safe work practices:

• Ensure air compressors are properly secured to prevent movement
• Periodically drain the moisture cock on dive compressors and visually inspect the fittings and connections to ensure these connections are secure
• When using the buddy system, ensure that both divers leave the water at the same time
• Dive tenders and dive supervisors must know the location of every diver at all times