How a toxic train crash became a presidential battlefield

When a train carrying toxic chemicals derailed in East Palestine, Ohio, on 3 February, only a small number of people outside the small town took notice. But in the weeks after it developed into a huge political row with national figures visiting the small town and the trains' operators being questioned by Congress.

The BBC's North America Correspondent Nomia Iqbal explains why.

Produced by Alex Lederman and edited by Joyce Liu.