An 18-year-old man has died after the car he was travelling in hit a wall.
Two other men aged 19 and 21 were seriously injured in the single-vehicle crash.
It happened at Woodstock, Ennis, Co Clare at about 4.20am on Sunday.
The injured men have been taken to University Hospital Limerick for treatment.
The road is currently closed to facilitate an examination by the Garda forensic collision investigators.
Gardai have appealed for anyone with information to contact officers at Ennis Garda Station.