Abstract: On the evening of January 4, 1988, during an asbestos removal operation, Employee #1 was phoned at home and asked by his supervisor to come to the work site to perform night duty. When he arrived, he was instructed to stand watch for a second abatement contractor and turn on the water valve inside the company's asbestos removal enclosure for the contractor's employees. The water access valve for both companies was inside the employer's enclosure. At approximately 11:00 p.m., Employee #1 told the contractor's employee to come and get him when they needed water, then proceeded to the company's enclosure to sleep. He closed off the clean area, which was 5 ft wide by 15 ft long by 7 ft high, and turned on a propane-powered Pelsue heater blower 1500 S. At approximately 5:00 a.m., the contractor's employee found Employee #1 dead in the small clean room enclosure. Employee #1 was asphyxiated by carbon monoxide from the propane heater, which he had run all night in the unventilated enclosure. His blood carboxyhemoglobin level was measured at 75.6 percent.