A five-year-old boy tragically died after the car he and his mother were traveling in crashed into a parked truck and trailer in the early hours of Friday.
Emergency services had to rescue the woman, 38, and her son from the rubble after the collision on Christies St in the western Sydney suburb of St Marys at around 3.20am.
The couple was treated at the scene by aambulance crews before being rushed to Westmead Hospital.
Both were in critical condition before the boy died overnight.
A woman and child are fighting for their lives after the car they were traveling in crashed into a parked truck in St Marys, western Sydney.
Heartbreaking photographs from the scene showed a white hatchback crashed into the back of the truck.
Debris was seen strewn across the road and the rear trunk of the car had been lifted.
It is believed the mother was driving and the child was in the back seat.
Police set up a crime scene and launched an investigation into the cause of the accident.
Anyone with information about the incident is asked to contact Crime Stoppers on 1800 333 000.
Emergency services had to rescue the woman, 38, and five-year-old boy from the wreckage after the collision in St Marys, western Sydney, shortly after 3am on Friday.