Gardaí is investigating a ferocious court traffic that took place at Portroe and Garykennedy Road near Nenagh at about 5.30 on Sunday morning.
One man at the age of 20 was declared dead at the crime scene, and his body was removed at the Limerick University Hospital.
The dead man was not appointed by the Guard, but the locals believe he was from Nenagha.
The other three passengers in the car, two men at the age of 20, and one man in late teenage years, were taken to the Limerick University Hospital with life-threatening injuries.
The scene looked at the forensic investigators in the garrison, and the road was reopened.
No details of the circumstances of the accident are known and Gardaí is invoked to anyone who has information, especially those in the area at the time of the incident, who may have a dash on the dash to contact Gardaí in Nenagh on 067505050.