What went wrong at the Bhopal branch of the UCIL?
I'm sure you are referring to Union Carbide and the Bhopal Gas Tragedy.
Union Carbide had opened a branch in India to produce the pesticide carbaryl. The process of production involved the use of a chemical called methyl isocynate which is a very poisonous gas. The demand for the pesticide fell sharply during the 1980s and this led to excess inventory of methyl isocynate which the company had to store as it cannot be disposed.
What actually went wrong at Bhopal was Union Carbide's cost reduction plan which came at the expense of safety and the lives of millions of Indians.
The company reduced the number of employees in the plant drastically. None of the safety norms were adhered to. According to an investigation done after the incident it was found that the tragedy could have been easily avoided if the company had not left the refrigeration system idle; the flare tower and the system to treat any escaping gas with sodium hydroxide had been working; and the pipes and valves had been replaced as required.
Union Carbide was able to do what it did due to the poor enforcement of rules and regulations in India; something that will always stay in the minds of millions who were disabled due to the gas leak and could never get justice.