Rail services had to be halted after a lorry struck a bridge in Seaham.
The truck is believed to have hit the structure between Mount Stewart Street and Hill Crescent in Dawdon, Seaham, at around 2.40pm today and then drove off.
Only the paintwork of the bridge was damaged, but services between Sunderland and Hartlepool had to be stopped while Network Rail carried out checks.
Services resumed at 3.25pm, with no knock on affect to trains.
Anyone who witnessed the truck collide is asked to call the number noted on the signs attached to each side of the bridge.