Abstract: Employee #1, the operations plant superintendent for a small cottonseed processing plant, was overseeing the seed oil processing at the indoor unit. The raw seed oil was being transferred in batches by a 100 psi positive displacement type pump from an open settling tank through a filter press and into a larger storage tank nearby. This 6 ft diameter by 10 ft tall vertical tank was normally emptied into an outdoor bulk storage tank when it reached the half full mark. Employee #1 was near the filter press, demonstrating something for the vice-president of operations, when the nearly full 2,000 gallon storage tank overpressurized and failed along the top rim. The large steel lid blew off with explosive force and struck the ceiling of the building approximately 25 ft above, damaging the steel framework. It then flew like a saucer to the ground, striking Employee #1 on the back of the head and just missing the vice-president. It then bounced numerous times on the concrete floor of the building before coming to rest. Employee #1 was killed. Subsequent investigation revealed that the tank was being operated with minimal gauges/instrumentation and without pressure relief.