From Sathyu’s Introduction to Bhopal for Young People
On December 2nd, 1984 a few workers were told to clean the pipes that carried the deadly MIC. The cleaning was being done by a high pressure jet of water. Because of the unsafe condition of the factory a lot of the water went inside the tank that contained MIC. This water started reacting with the MIC which made it hotter and made the reaction happen even faster. Soon there was so much heat and so much pressure inside the tank that the valve on the tank broke and about 40 tons of MIC gas leaked from the factory from a pipe about 100 feet tall. It was a few minutes past midnight when the leak started.
There was a gentle wind blowing towards the south which was where most people lived. The factory bosses could have sounded the siren to warn people about the gas leak, they could have told people to put a wet cloth over their noses to protect themselves, they could have advised people to run in the direction opposite to that of the wind. They did none of these and just went on denying that the deadly gas clouds had leaked from their factory. Because it was a very cold night, the clouds came down and moved close to the ground towards the centre of the city.