At approximately 3:15 pm on may 9, 1986, employees started to charge the number 1 line carbo-cooler, using a cylinder containing 150 pounds of anhydrous ammonia at 129 psi (room temperature). Employee #1, in an effort to speed the charging process, was adding water at 132 degrees to the ammonia cylinder (to raise the internal pressure). Employee #2 was working on 2 magnetic switches located near the sight glass on the carbo-cooler. Employee #3 was operating the #1 line filler, approximately 25 feet from the ammonia cylinder. Employee #4 was painting in aisle #3, approximately 45 feet from the cylinder. At approximately 3:30 pm the cylinder ruptured, producing a white cloud of ammonia gas. Employee #1, who was approximately 5 feet from the cylinder, was burned in the eyes and body and admitted to the hospital. Employee #2 was also admitted to the hospital. Employees #3 and #4 were both treated had released at the hospital. All employees re-entered the plant at 5 pm. The anhydrous ammonia cylinder had a 21 inch long split in it, approximately 3 1/2 inches wide at the widest spot. On Sunday, May 18, 1986, employee #1 died at Loyola University burn center, Chicago, Illinois.