Abstract: Employees #1 and #2 were attempting to pull a pump away from its casing. The impellers on the pump were in the casing. Employee #1 was between the pump and a 320,000 gal tank which was two-thirds full. A valve normally used to shut off the hydraulic pressure from a 12 in. pipe coming from the tank would not close. The liquid in the tank was 180 to 185 degrees Fahrenheit and had a pH level of 12 to 12 1/2. Employees #1 and #2 had left three to six bolts in the pump. Employee #2 obtained a pry bar and wedged it between the pump and its housing to move the pump away from its casing. The liquid pressure from the tank stripped the bolts out of the pump and pushed it out of its casing. Black liquid poured out of the casing like a fire hose onto the two employees. Employee #1 was burned over 55 percent of his body and was sent to a burn center, where he later died. Employee #2 was also burned, but was treated by the plant nurse after a local hospital had seen and released him on the day of the accident.