Irish Rail says its unacceptable that passengers weren't informed that services had been suspended at Heuston Station.
Over 20-thousand people were delayed after a major signal fault brought trains to a standstill.
Services to and from Heuston have resumed, but are experiencing some knock on delays.
The fault hasn't been fixed but a manual signalling system has been put in place.
Due to a major signal fault. There are currently no services operating into and out of Heuston. This includes Newbridge/Hazelhatch to Grand Canal Dock services. DART, Commuter and Intercity services into and out of Connolly are not impacted. Update to follow
— Iarnród Éireann #StaySafeSaveLives #HoldFirm (@IrishRail) May 28, 2019