The collapsed line was first spotted by the driver of the 6.07pm train travelling from Balbriggan to Pearse Station. It is believed he was approaching the site at around 6.30pm. The driver had passengers on board but stopped in time.
Iarnród Éireann said initial examinations suggest subsidence caused the structure to give way. A full investigation into the incident began last night. Up to 20 metres of the bridge collapsed.
Iarnród Éireann spokesman Barry Kenny said last night that the incident “had the potential to be a serious tragedy”.
“This was a busy time at the railway and we are extremely relieved that there was no injuries,” he said.
Northern commuter services are seriously disrupted as a result. A shuttle rail service is operating today between Drogheda and Skerries only. Customers travelling between Dublin city and all stations north of Malahide are advised to travel by Dublin Bus or Bus Éireann services.
Trains are running between Belfast and Drogheda, with bus transfers between Drogheda and Connolly. Passengers using the bus transfer can expect delays in reaching Connolly.
Weekday service details were being organised last night by Iarnód Éireann.
DART services between Malahide and Howth Junction are operating normally. Iarnród Éireann management says the line across the estuary will not reopen for several weeks, at the least.