5 teenagers were brought to Cork University Hospital after a single car crash at Monearmor in Youghal at around 9:20pm that night.
A 17 year-old boy suffered serious injuries, while two other teenage boys and two girls in their late teens were also injured.
Gardaí are appealing to anyone who was in the area between 9 and 9:30pm who may have witnessed this incident or anyone who may have camera footage (including dash cam) to contact Gardaí in Youghal on 024 92200, the Garda Confidential Line on 1800 666 111 or any Garda station.
