Abstract: Between 6:30 and 7:30 a.m. on February 28, 1987, Employee #1, a line operator, and five coworkers were working on the #1 furnace in the conveyor area, cleaning off excess burden spillage on and around the conveyor system. The #1 furnace (phosphorus) had been shut down on February 2, 1987, and blocked off the night before the accident for maintenance and cleanup work. Between 7:20 and 7:30 a.m., Employee #1 was cleaning underneath the #2 tail-end feedback conveyor when coworkers noticed that he was experiencing physical problems. CPR was administered, but Employee #1 had died. According to the medical examiner, the cause of death was overexposure to carbon monoxide. At the time of his death, Employee #1 was not wearing an air-supplied respirator. The work area was designated as a potential carbon monoxide exposure area.