Abstract: Employee #1 and a coworker were performing a service operation at a crude oil storage tank facility. They were performing a tank rollover in which they pumped crude oil from a storage tank into a tanker truck where it was heated to separate out the water and then they pumped it back into the storage tank. The tank system had a flare stack to burn off accumulations of flammable gasses. Instead of connecting the truck to the line in the tank, the employees opened a hatch on top of the tank. This produced pressure to the flare causing it to go out. The unburned gasses then accumulate and migrated to a source of ignition which could have been the burners on the truck, the truck itself, or employees smoking in the area. An explosion occurred and Employee #1 was engulfed by the fire and killed.