The operator connected a steam line to the tube-side of the exchanger in order to clean the exchanger. The steam
quickly heated up the ammonia, and with the shell-side effectively isolated the pressure began to build up as the liquid
ammonia began to evaporate. Less than an hour later the heat exchanger shell violently ruptured spraying the area with
metal shrapnel and releasing dangerous levels of ammonia to the atmosphere. Five nearby workers were exposed to the gas and had to be treated.