Gardaí are investigating the fatal single-vehicle collision which occurred on the R518 Askeaton to Rathkeale Road, Co Limerick at around 1am this morning.
One male passenger in the vehicle, aged in his 20s, was pronounced dead at the scene and has been removed to University Hospital Limerick (UHL) for a post-mortem.
Another male passenger, also in his 20s, was taken to UHL to be treated for non-life threatening injuries.
The male driver of the vehicle, aged in his late teens, was arrested at the scene and taken to Henry Street Garda station where he is currently detained under Section 4 of the Criminal Justice Act, 1984.
The road is currently closed with local diversions in place as Garda forensic collision investigators conduct a technical examination of the scene.
Gardaí are appealing for any witnesses to the collision to come forward. They are also asking any road users who were travelling on the R518 at Cragmore Askeaton at the time who may have camera footage to make it available.
Anyone with information is asked to contact Henry Street Garda station on 01 801 0600, the Garda Confidential Line on 1800 666 111, or any Garda station.
