Abstract: Two employees were cutting four bolts off a value flange on a vegetable oil line in a food processing plant using an oxygen and acetylene torch. Employees #1 and #2 thought the line was isolated and depressurized, but oil had just pumped through the line that was filled with 60-80 lbs of air pressure to blow the oil residue out of the line. As they cut off the third bolt, the line began to leak an oil mist. Employees #1 and #2 were enveloped by the mist when the torch ignited the mist resulting in a 40-ft fire ball. Employee #1 was burned over 100 percent of his body and died several hours later. Employee #2 was burned over 50 percent of his body and was hospitalized. Neither employee verified that the line was safe and isolated prior to cutting into it.