Set against the backdrop of 1984’s Bhopal gas leak tragedy, known as the world’s worst industrial disaster, and inspired by true stories from the events, the series is billed as “a thrilling account of courage and a salute to humanity.”   It will showcase the efforts of the disaster’s unsung heroes — the railway employees of India, who went beyond their call of duty, trying to save the lives of hundreds of innocent citizens trapped in a helpless city. Cast includes R Madhavan, Kay Kay Menon, Divyenndu and Babil Khan.   At least 3,787 people were killed in the incident, a chemical accident that exposed hundreds of thousands to lethal gases. There are claims the death toll is actually much higher.