What were the reasons for the bhopal gas tragedy in simple words

What were the reasons for the Bhopal gas tragedy in simple words answer for exam of class8

The Bhopal Gas tragedy occurred on 3rd December, 1984 at a Union Carbide subsidiary in Bhopal. There was no process of production being carried on at that time. The main cause of this tragedy was the water entering into the tank of Methyl Isocyanate. This caused a reaction which lead to the release of toxic Methyl Isocyanate gas. The release of this toxic gas resulted in the death of thousands of people and caused irreversible harm to the environment.