Abstract: On December 19, 1989, quarterly maintenance on plant and machinery started at 7:30 a.m. The incident occurred in the production area where a forklift was being used to lift employees to the rafters where they blew off dust and lint. Employee #9 alternately drove the forklift and blew off dust until 9:30 a.m. The forklift was left running most of the time. Employee #3 was cleaning a dust top and Employee #2 was using a dust bag. All other employees were doing various cleaning tasks. During a work break taken at 9:30 a.m., employees complained of headaches and nausea. All employees started feeling weak, dizzy, and nauseated. Employee #1, who was pregnant, vomited three times during the work break. An ambulance was called at 10:30 a.m. Employees #1 through #9 were taken to various hospitals. All were diagnosed to be suffering from carbon monoxide poisoning. Carboxyhemoglobin levels ranged from 16 percent to 26.9 percent in the employees. With almost no ventilation in the work area, the poorly tuned forklift left running produced carbon monoxide.