The 1984 Bhopal gas tragedy was caused by the leakage of

The disaster occurred at a pesticide plant, where methyl isocyanate (MIC), an intermediate in making carbamate pesticides, leaked on the night of 2-3 December 1984. Phosgene is also used in the process but MIC was the leaked gas. Methane and chlorine were not involved. MIC reacts violently with water, which triggered the release.