The actions of police in a deadly chase with a stolen car will be probed as the force stresses the tragedy could have been avoided.
A teenage boy was killed and four other people taken to hospital after the stolen car crashed at Scone in NSW's Hunter region.
The car was picked up travelling at high speed on the New England Highway at nearby Aberdeen just before midnight on Saturday, with police initiating a pursuit.
It was reduced to a wreck off the side of the road, about 100 metres north of Makybe Diva St.
The car's driver, a 14-year-old boy, and front-seat passenger were trapped before being freed and treated by paramedics.
The passenger, a 17-year-old boy, died at the scene.
The driver was flown to Newcastle's John Hunter Hospital, where he and three back-seat passengers - two boys aged 14 and 17 and a 25-year-old woman - were all were treated for non-life threatening injuries.
"It is a unnecessary tragedy on our roads," Acting Assistant Commissioner Chad Gillies told reporters on Sunday morning.
Police believe the car was stolen from a Wallsend business on Saturday afternoon.
Based on initial information, all the boys are from the Tamworth area and the woman is from the Newcastle area.
Mr Gillies wasn't prepared to comment on whether the driver was known to police or how the woman knew the teenagers.
The stolen car performed an undertake on another vehicle driving through Scone before the crash.
The driver of that car has been encouraged to contact police to provide information but isn't in trouble.
Along with calling in crash investigators, NSW Police have established a critical incident investigation team.
While not uncommon, police pursuits are governed by strict rules and assessment processes.
"That will be subject to this investigation in terms of the actions of police in the pursuit aspect itself," Mr Gillies said.
The critical incident investigation will be independently reviewed by the Professional Standards Command and overseen by the Law Enforcement Conduct Commission.
