The driver of the car, a man in his 30s, was removed from the scene and later pronounced dead
The two-vehicle collision occurred at approximately 3.55pm yesterday on the N77 between Kilkenny town and Ballyragget.
The driver of the car, a man in his 30s, was removed from the scene and later pronounced dead at St Luke's General Hospital Kilkenny.
A female teenager who was in this vehicle was taken by air ambulance to Waterford University Hospital with serious injuries.
The three occupants – two males in their 40s and 60s and a woman in her 40s - of the second vehicle were taken to St Luke's General Hospital Kilkenny for medical treatment.
It's understood that their injuries are non-life threatening.
As part of the investigation, Gardaí are looking at the circumstances of the theft of a vehicle at Green Street, Kilkenny at approximately 3.30pm yesterday.
A garda spokesperson said: “A female teenager was an occupant of the vehicle when it was stolen.
"This vehicle was subsequently involved in the fatal road traffic collision.”
The N77 between Hennebry's Cross and Dinan Bridge remained closed overnight, and the services of Forensic Collision Investigators have been requested.
Gardaí are appealing for any witnesses to either of these incidents to come forward to assist them with their ongoing investigations.
Any road users who may have camera footage (including dash-cam) and were travelling on the N77 between Kilkenny town and Ballyragget between 3.15pm and 4pm are asked to make this footage available to Gardaí.
Gardaí are also appealing for any road users who may have camera footage (including dash-cam) and were travelling in the Green Street area of Kilkenny between 3pm and 3:30pm to make this footage available to them.
Anyone with any information is asked to contact Kilkenny Garda Station on 056 7775000, the Garda Confidential Line on 1800 666 111, or any Garda Station.