A Sydney community is in shock after two young children died following a devastating collision involving a pram and a vehicle in Cabramatta on Wednesday afternoon.

Emergency services rushed to the intersection of Joseph Street (Cumberland Highway) and Gilbert Street at approximately 3:15pm following reports that a vehicle had struck a pram carrying two children.

According to NSW Police, the children, aged one and five, suffered critical injuries in the collision. Paramedics from NSW Ambulance immediately began emergency treatment at the scene before both children were transported to The Children's Hospital at Westmead in critical condition.

Despite extensive efforts by medical teams, the children later died from their injuries.

Police said a 33-year-old woman, who is known to the children and was accompanying them at the time of the incident, sustained minor injuries and was treated at the scene.

The driver of the vehicle, a 56-year-old man, was not physically injured. He was arrested at the scene and subsequently taken to hospital for mandatory testing, which is standard procedure following fatal road incidents in New South Wales.

Major Crash Investigation Unit detectives have commenced an investigation into the circumstances surrounding the tragedy. Authorities are expected to examine witness statements, CCTV footage, vehicle data and forensic evidence from the scene to determine exactly how the collision occurred.

The incident caused significant disruption to traffic across the area, with Cumberland Highway closed southbound between John Street and Cabramatta Road while investigators conducted their examination. Motorists were urged to avoid the area and seek alternative routes.

The deaths have sent shockwaves through the local community, with many residents expressing grief over the loss of two young lives. Emergency responders, including police, paramedics and firefighters, attended the distressing scene and worked for several hours as investigations continued.

Road safety experts note that incidents involving pedestrians, particularly children, are among the most tragic and complex crashes investigated by authorities. Determining the sequence of events is often crucial to understanding how such incidents occur and whether any contributing factors were involved.

Police have appealed for anyone who witnessed the collision or who may have dashcam footage from the area around the time of the crash to come forward. Investigators believe additional information could assist in establishing the circumstances leading up to the incident.

The matter remains under active investigation, and no charges have been announced.

Authorities will prepare a report for the Coroner as part of the formal process following the deaths.

The tragedy serves as a heartbreaking reminder of the vulnerability of young pedestrians and the devastating consequences that can result from serious road accidents.