Abstract: On or about November 30, 1995, Employees #1 and #2 were welding a ladder to the side and top of a 10,000 gallon waste water tank located at the Phillips pipeline terminal in East Chicago. Employee #1 was on top of the tank holding the ladder. Employee #2 was standing on the ladder and was welding the top of the ladder to the top of the tank. A hot piece of material fell into the flammable fumes in the tank, causing an explosion. The explosion blew Employee #1 off the top of the tank. He was killed. Employee #2 was thrown from the ladder. He sustained abrasions, a cut, and ear injuries. The tank was not ventilated.