Kaala Patthar is a 1979 Indian Bollywood action/drama film. It was produced and directed by Yash Chopra. The story was written by Salim-Javed. This film is the fourth collaboration between Amitabh Bachchan, Shashi Kapoor and director Yash Chopra after the hugely successful Deewaar , Kabhie Kabhie and Trishul . However, this film did average business at the box office. It was nominated for Filmfare awards. When Seth Dhanraj (Prem Chopra) makes lives difficult for the coal miners by giving them poor equipment, less than sufficient medical supplies and lack of facilities, Vijay, Ravi and Mangal forcefully come together to fight for justice against Dhanraj when water floods the mines endangering the lives of hundreds of workers. The disaster actually took place at a place called Chasnala in erswhile Bihar (now Jharkhand).Wikipedia