Just after midnight on 2 December 1984 a storage tank at the Union Carbide chemical plant in Bhopal began leaking a gas called methyl isocyanate (MIC). The plant, in Madhya Pradesh, India, was equipped with six safety systems designed to detect such a leak, none of which were operational that night. Twenty-seven tons of MIC gas spread throughout the sleeping city.
As an engineer was flushing water through a corroded pipe in the MIC production complex, a series of valves failed, allowing the water to flow freely into one of the three-storey tanks holding the toxic chemical in a liquid state. This caused a rapid and violent reaction. The tank shattered in its concrete casing and spewed a deadly cloud of MIC, hydrogen cyanide, monomethylamine and other chemicals, all of which hugged the ground.
