Gardai in Borrisokane are investigating a single vehicle fatal road traffic collision.
The incident occurred at Boston on the Ballingarry North to Cloughjordan road yesterday afternoon at approximately 3.45pm.
A 16-year-old male was fatally injured when the car he was a rear seat passenger in collided with a tree.
He was pronounced dead at the scene and his body was taken to University Hospital Limerick.
The two other occupants, a 22-year-old male and a 17 years old female, were taken to Tullamore Hospital and University Hospital Limerick.
The 22-year-old male is described as being in a serious condition.
This stretch of road was closed for a time to facilitate an examination by Garda Forensic Collision Investigators and has since reopened.
Gardai wish to appeal for witnesses to contact Nenagh Garda Station on 067 50450, The Garda Confidential Telephone Line 1800 666 111 or any Garda Station.