Major Crash Investigators are seeking information regarding a fatal crash in Kalgup, near Busselton, last night, Saturday 17 April 2021.
WA Police said they were advised of the crash on Doyle Road at around 8.50pm.
"It appears a grey Ford Falcon sedan was being driven east on Doyle Road, when it failed to negotiate a bend in the road, left the carriageway and struck a tree.
"At the time of the crash it is believed there were seven people in the vehicle, including two people travelling in the boot of the vehicle."
During a press conference, South West superintendent Geoff Stewart said seeing people die was 'the worst thing about being a copper'.
He said everyone that was in the car went to the same school in the South West but did not confirm which school it was.
Superintendent Stewart said police had been in contact with the Department of Education as well as the principal.
Police, Department of Fire and Emergency Services, St John Ambulance and two rescue helicopters were deployed to the scene.
The 17-year-old female driver of the vehicle was taken to Royal Perth Hospital by an RAC Rescue helicopter for treatment of serious injuries she received in the crash.
Two passengers, who were believed to be seated in the rear of the vehicle - being a 16-year-old boy and a 15-year-old boy - died at the scene.
The four remaining passengers - one girl and three boys aged 15-16 years old - were taken by ambulance to hospitals in Busselton and Bunbury.
Superintendent Stewart said he believed no one had life threatening injuries anymore.
Investigators are asking anyone with dash-camera or mobile phone vision of the crash scene, or the grey Ford Falcon sedan being driven prior to the crash, to upload the vision via this link:
Anyone with information regarding this crash, or who saw the vehicle being driven prior to the crash, is asked to call Crime Stoppers on 1800 333 000 or report the information online at www.crimestopperswa.com.au