On the evening of 2 June 2023, a devastating crash involving three trains killed nearly 300 people and injured more than 800 at Bahanaga Bazar station in India’s eastern Odisha state, as two passenger trains collided with a freight train. What caused one of the worst train disasters in modern history? This film forensically examines what went wrong and asks whether it could have been prevented and if enough is being done globally to ensure our railways are safe. The documentary explores what could have caused this disaster and, using case studies of other train accidents, unpacks the science and engineering behind them. It also investigates the pressure put on railway services by maintenance budgets, the greater need for upgrading ageing infrastructures and the significant impact of climate change.