A police investigation continues into the accident on the M5 motorway at Beverly Hills, in which three teenage girls were critically injured.
The long-time friends, together with one of their brothers, were travelling east on the motorway when their car slammed into the rear of a bus parked in the breakdown lane.
Faith Patolo-Vitale, 19, was the driver of the red Mazda and her brother, Aliamanu Patolo-Vitale, 18, was the front seat passenger. He was taken to hospital in a stable but serious condition
Shalaney Velasquez, 19, and Lisa Aitoa, 18, were in the back seat rear of the Mazda.
The bus was empty at the the time of the crash on Sunday evening.
The teenagers had to be cut from the wreckage of the car.
Ms Patolo-Vitale and her brother were taken to St George Hospital, while the other teenagers were taken to Liverpool hospital.
Three young women were critically injured when the car in which they were travelling crashed into a stationary bus in a breakdown area on the M5 motorway at Beverly Hills.
Emergency services were called to the M5, between Belmore Road and King Georges Road, about 6.25pm on Sunday.
Police were told a Mazda, travelling east on the M5, crashed into the rear of a bus, that was stationary in the breakdown area on the side of the road.
"The female driver, aged 19, and a female rear passenger, aged 18, were trapped for a short time, before being released by Fire & Rescue NSW," a police spokesman said.
"All four occupants, including a male front seat passenger and female rear passengers, aged 18 and 19, were treated at the scene by NSW Ambulance Paramedics, before two women were taken to Liverpool Hospital and a man and woman were taken to St George Hospital.
"The three women are in a critical condition and the man is in a serious but stable condition.
"The driver of the bus was uninjured and there were no passengers on-board at the time.
"Officers from Campsie Police Area Command, with assistance from officers attached to Bankstown Traffic & Highway Patrol, attended and established a crime scene.
"It was examined by specialist officers from the Metropolitan Crash Investigation Unit.
"As investigations continue, police are urging anyone with information or dashcam footage to contact Crime Stoppers on 1800 333 000."