The accidental release of methyl isocyanate gas from the Union Carbide pesticide plant in Bhopal, India, immediately killed at least 3,000 people and ultimately caused 15,000 to 20,000 deaths.

Another 500,000 survivors have since suffered ailments related to the disaster.

The company paid $470 million in compensation to the victims, and several former employees were convicted of death by negligence in relation to the incident.

Yet, it maintains that it is not to blame for the gas release. Why?