Some of the thousands of people stricken by a poisonous gas leak from a Union Carbide pesticide factory in Bhopal, India, on Dec. 4, 1984. Poisonous chemicals leaked from the plant during the night. A leak of 40 tons of poisonous gas from a Union Carbide pesticide plant on Dec. 3, 1984, killed at least 10,000 people in this central Indian city and affected more than 555,000 others, although the exact number of victims has never been clear. Many died over the years due to gas-related illnesses, like lung cancer, kidney failure and liver disease. (AP Photo/Sondeep)