On this day, 40 years ago, on August 21, 1985 (July 6, 1985, the lunar calendar), a toxic gas leak occurred at a factory of Union Carbide Company. On the morning of August 21, 1985, a small plume of toxic chemical smoke leaked from a Union Carbide plant near Charleston, West Virginia. At least 135 residents have been treated for inflammation of their eyes, throat and lungs. The accident angered many local residents. In December 1984, a methyl isocyanate toxic gas leaked from a Union Carbide factory in India, killing 2000 people.