Abstract: A double compartment fuel tanker owned by a wholesale fuels company was received by the maintenance shop of the service center on July 9, 2002, to repair a crack in a previously welded division head pad. The top manholes on the tanker were left open over night to vent and evaporate any residual fuel film on the interior liquid contact surfaces. The tank was aerated on July 10, 2002, in accord with company standard operating procedure. The shop supervisor issued and posted a confined entry permit after air monitoring results showed that the tank compartment was in compliance with the regulatory requirements for confined space entry and the tank was again vented overnight. On July 11, 2002, Employee #1, an experienced welding mechanic, was assigned and directed to perform the repair work by the shop supervisor. Employee #1 aerated the tanker and retested the atmosphere in the compartment with the same multi-gas monitor used by the shop supervisor on July 1 0, 2002. The instrument had a current factory calibration record for Model ATX612, Serial Number 0101285-114, manufactured by Industrial Scientific Corporation. The instrument readings for all gases of concern were at or below the regulatory requirement for confined space entry. Employee #1 entered the compartment and started welding the pad at approximately 0915 hours. At approximately 9:25 a.m. a flame of ignited gasoline vapors, approximately 8 ft long, shot across the tank compartment pinning Employee #1 against the opposite side wall of the tank. Employee #1 screamed for help and since no one came to his immediate rescue; he decided to jump through the flame and climbed out the manhole at the top of the tank. A coworker who was in the immediate area of the tank contacted the shop supervisor and told him that "Employee #1 had started a fire". The shop supervisor immediately ran over to the tank, climbed up the tank ladder, and helped Employee #1 down, and sat him on a chair. Employee #1 sustained second-degree and third-degree burns to his thighs and arms and inhalation burns to his lungs. Employee #1 was hospitalized.