Abstract: On May 19, 1989, Employees #1, #2, #3, and another worker were installing a fixed ladder to the south side of a 500,000 gallon storage tank used for storing industrial waste water contaminated with petroleum products. Employees #2 and #3 were located on the top of the tank to assist in raising the ladder. Employee #1 and another worker remained on the ground to weld the lower supports for the ladder. After welding the lower supports in place, Employee #1 went to the top of the tank to weld the top support brackets. Employee #1 had completed the left bracket and had just started the right bracket when a fire and an explosion occurred. Employee #1 was blown from the top side of the tank and fell approximately 30ft, sustaining fatal injuries. Employee #2 was blown from the tank horizontally, approximately 15 ft and downward, approximately 30 ft, sustaining critical injuries. Employee #3 was blown upward approximately 10 ft and fell back onto the top of the tank sustaining numerous cuts and bruises. He was rescued with the use of a portable extension ladder.