A boy who died early on Tuesday near Killimer, Co Clare may have been lying on the roadside when a passing car drove over him.
The driver of the vehicle stopped and returned to the scene where she found the 15-year-old partially lying in the ditch. The woman immediately raised the alarm.
With instructions being relayed down the phone by ambulance controllers, the woman performed cardiopulmonary resuscitation (CPR) on the young man until paramedics arrived.
Gardaí from Kilrush along with ambulances from Kilrush and Ennis responded to the emergency call. The teenager was pronounced dead at the scene.
The body was latertaken to University Hospital Limerick while the office of the State Pathologist was informed. Assistant state pathologist Dr Margaret Bolster was carring out a post mortem examination.
Gardaí will await the results of the post mortem before they determine the course of their investigation. It is hoped the autopsy will tell gardaí whether the victim died as a result of being struck by the vehicle or earlier in another way.
The road remained closed while a technical examination was carried out.
The tragedy happened close to Killimer GAA Club a short distance from the village of Killimer and about 7kms from Kilrush. Gardaí are trying to determine whether the young man was on his way to meet friends who had been socialising in the area or if he was on his way home.