Abstract: At approximately 9:00 a.m. on January 18, 1990, contract employees were replacing pipe at the flammable liquids tank farm of RJ Reynolds Plant #604, Winston-Salem, NC. They heard a sound similar to pressure being released or relieved, which was followed immediately by a blast -- the entire top of the methyl ethyl ketone tank (tank #4 in the farm) had blown off and was fully engulfed in flames. The local fire department and the plant's fire brigade were summoned. The fire was extinguished in approximately one hour (around 10:00 a.m.). The tank involved in the fire was heavily damaged and some of the surrounding tanks sustained damage, but no employees of the contractor or RJ Reynolds were injured.