Abstract: On February 23, 1999, Employees #1 and #2, pipefitters, were engaged in a maintenance activity to remove and replace the naphtha draw piping, which had developed a leak, due to ammonium chloride corrosion. The employer decided to make the repair, while the process unit remained in operation, but failed to isolate the naphtha piping from the operating process prior to cutting into the line. The highly flammable gasoline-line, benzene-containing hydrocarbon flowed through openings in the line and onto the hot surfaces in the operating unit. The naphtha ignited, causing a fire near the bottom of the tower, which spread up and down the tower, engulfing both employees. Employee #1 was hospitalized for his burns, but Employee #2 died.