Gardaí arrested a man in his 20s at the scene - he can be held for up to 24 hours.
One person has died, another is in a serious condition and a man has been arrested after a crash in Dublin early this morning.
One car was involved in the collision on the N2/M50 slip road, which happened shortly after 1 o'clock.
A man in his 20s has died and a woman in her 30s has been taken to the Mater Hospital with serious injuries.
Gardaí arrested a man in his 20s at the scene - he can be held for up to 24 hours.
A technical examination is underway and the road is expected to re-open soon.
Gardaí are appealing for witnesses.

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