Many of the barges that had been traveling on the Mississippi River were engulfed by the hurricane. One of the barges, "MTC-602", contained 600 tons of deadly chlorine gas contained in cylinders. Chlorine gas, which was used frequently as a chemical weapon in World War I, is a powerful irritant that can inflict damage to the eyes, nose, throat and lungs, and (at high concentrations and prolonged exposure) cause death by asphyxiation. It was estimated that the amount of chlorine loaded on the barge was enough to kill 40,000 people. The barge had sunk near Baton Rouge, where an estimated 300,000 people lived. The residents in the harbor area were evacuated until the barge was recovered. President Lyndon B. Johnson ordered the Navy and Army Engineers to find and raise the barge. While it took months to locate and make the appropriate plans for raising the barge, the actual process of raising it took around two hours. The barge was reportedly recovered, without any problems, on November 12, 1965.