All northbound DART services from Connolly Station have been cancelled until tomorrow afternoon at the earliest after debris from an overhead bridge damaged power lines.
A spokesman for Iarnród Éireann said the Belfast Enterprise service and Drogheda commuter trains would also experience delays this afternoon until the debris was removed from the line.
Water pipes on an overhead bridge are understood to have fallen onto the overhead power cables just after 12.30 p.m., causing significant damage.
Iarnród Éireann expects the clean-up and repair operation will take at least 24-hours meaning significant delays for commuters - many of whom will be returning to work tomorrow morning.
Southbound services from Connolly Station are operating normally.
