The Moss Vale teen, who cannot be named for legal reasons, was overtaking on double unbroken lines, around a blind corner when he lost control of his Ford Falcon shortly after 6pm on April 18.

The car careered down an embankment on the opposite side of the road, hitting several trees before coming to rest on the driver’s side.

The teen, along with his 20-year-old step-brother, who was sitting in the front passenger seat, managed to scramble out of the vehicle through the front windscreen, as several motorists came to their aid.

However, the boy’s 15-year-old sister, who was seated behind her brother, remained trapped in the car with serious injuries.

It took emergency service personnel more than 90 minutes to free her from the wreckage.

She was airlifted to St George Hospital, while both males were taken to Wollongong Hospital by road ambulance.

An agreed statement of facts tendered to Wollongong Local Court yesterday said the girl received ‘‘unsurvivable brain injury’’ as a result of the crash.

She remained on life support in order for her organs to be donated, however was declared dead the following day.

The court heard the male passenger suffered only whiplash and an injury to his finger, while the driver received fractures to three vertebrae.

The police fact sheet said the car was inspected for any possible defects that may have contributed to the crash, however none were found.

The teen pleaded guilty to a single charge of dangerous driving occasioning death in court yesterday.

The matter has been adjourned to Wollongong District Court for sentencing on November 15.