Two people are understood to have been hospitalised with suspected spinal injuries following a crash involving a Luas tram and a truck this morning.
Five units and two ambulances from Dublin Fire Brigade attended the scene after the crash near the Cheeverstown stop.
As a result, the service is only running from Tallaght to The Point with all services between Saggart and Belgard currently suspended.
Those looking to travel from Saggart will have to use Dublin Bus services - Luas tickets will be valid.
AA Roadwatch says: "Following an incident involving a Luas and a truck, the Red Line is not running between Saggart and Belgard and will only operate between Tallaght and the Point."
Elsewhere, traffic is understood to be moving well along the M50.
Stick with us for all the latest traffic updates as rush hour descends on the capital.