A three-month-old girl has died after a collision between a car and cement truck south-west of Sydney that also killed her mother and older brother.
The crash occurred on the Hume Highway at Menangle Park, in the Macarthur region, about 11:20am on Monday.
Police said the critically injured infant was airlifted to the Children's Hospital at Westmead after she was pulled from the wreckage.
Ivy Sila died early on Wednesday morning, becoming the third family member to have died after the crash.
Her mother and the SUV driver Katrina Sila, 34, and two-year-old brother Kai, died at the scene.
A 48-year-old male truck driver was not injured and was taken to hospital for mandatory testing.
Footage from the scene shows emergency services attempting to gain access to a heavily damaged car.
At the time, NSW Ambulance chief superintendent Mark Gibbs said he found it hard to believe "anyone could survive the wreckage".
"This was a challenging scene for our paramedics to attend, with two patients deceased and another young child who was trapped in the vehicle," chief superintendent Gibbs said on Tuesday.
"Paramedics and two specialist medical teams worked alongside Fire and Rescue NSW to free the child, who was then intubated on scene before being airlifted.
"This is a very tragic incident and our thoughts are with the family of those involved."
He said it was too early to know where the children were seated at the time.
Officers established a crime scene and are continuing to investigate the circumstances surrounding the collision.
Investigators urged anyone with dash cam footage of the area at the time, or anyone with information, to come forward.
A report is being prepared for the coroner.
