Bhopal gas tragedy occurred on 3 Dec. 1984 in a Union Carbide pesticide plant. When water and MIC mixed, an exothermic chemical reaction started, which produced a lot of heat. As a result, the safety valve of the tank burst because of the increase in pressure. This burst was so violent that even the concrete around the tank also broke. The high moisture content (aerosol) in the discharge while evaporating gave rise to a heavy gas which rapidly sank to the ground. It caused several of the following ailments like partial or complete blindness, disorders like, gastrointestinal disorders in many surviving people.