Abstract: Employee #1, of Coastal Refining and Marketing, Inc., was working as a coker helper in the delayed coking unit, switching the drums, blowing down the west drum, and cooling the west drum. Employee #1 and his lead operator were in the unit to open the main drain line and the alternate drain line, when Employee #1 opened the wedge plug on the alternate drain line on the east drum instead of on the west drum. Hot feed oil was being pumped into the east drum when the wedge plug was opened. Hot oil drained out the drain line into the sluiceway and was ignited. A flash fire occurred and Employee #1 sustained fatal burns. The lead operator was approximately 15 feet away and did not sustain any burns.