A lethal plume of methyl isocyanate (MIC) gas escaped from a storage tank at the Union Carbide pesticide factory in the early hours of Dec. 3, 1984 in the central Indian city of Bhopal. Investigators concluded that water leaked into the tank, causing a reaction that triggered the release. One study suggests sabotage could have been to blame. MIC is a highly toxic, sharp-smelling gas used in the production of pesticides, rubber and adhesives. __