The Bhopal disaster. Early in the morning on Dec. 3, 1984, a holding tank at a pesticide plant owned and operated by Union Carbide, released a large volume of poisonous gases into the city of Bhopal, India. Thousands died immediately, and an estimated 20,000 have died since then, apparently from gas-related symptoms. Another 100,000 to 200,000 people are thought to have been severely sickened by the gas. Union Carbide, now owned by the Dow Chemical Company, maintains that the gas leak was caused by deliberate sabotage, although company officials have been warned of repeated safety violations beforehand. To date, nobody has been prosecuted. In this photo, activists in Bhopal demonstrate on the 25th anniversary of the disaster.