A collision, which occurred at 7:30 pm on Friday on Mountain Road, just outside of Clonmel, has claimed the lives of four young people - the driver, a man in his 20s, and three teenage girls.
It's been confirmed the three teenage girls had gotten their leaving cert results only hours before, and it's believed they were on their way to a gathering to celebrate.
Mountain Road remains closed and Forensic Collision Investigators are examining the scene today.
An incident room has been set up at Clonmel Garda Station, and support will be available for those affected at C-SAW House in Clonmel between 4 pm and 8 pm on Saturday and Sunday.
Gardaí are appealing to anyone who was in the area at the time or might have dashcam footage to contact them.
They also say images of the immediate aftermath of this incident are being shared on social media and are asking the public not to share any of the material.
The Taoiseach, Tánaiste, and Minister for Education have all described the tragedy as "heartbreaking".
Leo Varadker has described the deaths of the four young people as "truly devastating and heartbreaking", while Micheál Martin has said he is "deeply saddened" by the tragic loss of life.
Norma Foley says the department, through the National Educational Psychological Service, will provide essential support to staff and students.