Abstract: Employee #1, the driver of an over-the-road tank truck loaded with ammonia hydroxide, was in the vicinity as his tank was being unloaded into a polyethylene storage tank at the site of a chemical distributor. The unloading was being accomplished by filling the vacant space above the liquid inside the cargo tank with compressed air, a standard method of unloading such tanks. When the cargo tank was emptied, the compressed air surged into the polyethylene storage tank, which was not designed to withstand that kind of pressure. The polyethylene tank ruptured, releasing a substantial volume of ammonia into the air. Employee #1, who was close to the drain valve on the cargo tank, inhaled a substantial volume of ammonia, He suffered serious chemical burns to his lungs, resulting in his death.