Abstract: Employee #1 was engaged in unloading and reloading a reactor vessel with new catalyst material used in desulfurization. He was regularly entering the reactor to verify the depths of various layers of catalysts and, for some reason, returned to the vessel without the proper personal protective equipment and without anyone knowing he had entered. Employee #1 was found dead inside the reactor vessel when reloading was only hours away from being completed. The process mandated compliance with the permit-required confined space standards, and Employee #1 had been properly equipped with a supply air respirator. The cause of death was ruled as hypoxemia, or inhalation of oxygen poor air. The coroner's official ruling was undetermined in regard to how Employee #1 's death occurred. The Sheriff's department's findings were also inconclusive, with no apparent evidence of homicide or suicide. At the time of the accident, Employee #1 was working for a contractor of the Ashland Petroleum Company.