Ireland's worst traffic jam occurred after a series of events that were described as the 'perfect storm' for major traffic disruption.
Dublin City Council's water department started xing a burst water pipe on the N11 without informing the council's transport department responsible for traffic management.
Previous work on the road had seen a contra-flow system set up under which a lane running north was used for trafc leaving the city. This did not happen.
Because there was no communication between the two departments, no warning was given about the works.
The works took place during the rush hour of traffic leaving the city.
Garda traffic patrols didn't pick up on the growing traffic jam until it was too late.
Roadwatch didn't send out any bulletins to the local media.