 The script was jointly written by Kumar and David Brooks Miller. In order to present the correct technical and medical facts in the film, Kumar analysed documents of the court proceedings, forensic evidences and interviewed several survivors of the tragedy and also the staff members of the Union Carbide plant. Bhopal Group for Information and Action and many activists fighting for the rights of the victim of the disaster wanted to stop the film's screening, called it an insult to the victims, blamed the filmmakers of distorting the facts related to the disaster, diverting attention from Dow Chemical Company which acquired Union Carbide in 2001 and for portraying Anderson as a person who wanted to help the people but was unable to do so. Sheen denied these allegations and said that he did not sympathise for Anderson. Kumar also denied these allegations and said that the organisations had seen an older script. He added that making the film was a life-changing experience for him. A Prayer for Rain was added to the film's title because had it rained on the night of 2 — 3 December 1984, fewer people would have died.
