A woman and child have been killed in a two vehicle crash at Menangle Park.
Around 11:20am a cement truck and silver SUV crashed in the northbound lanes of the Hume Motorway.
The female driver and a child in the SUV died at the scene.
The Toll Rescue helicopter was called in, with a medical team assisting Paramedics treat a second child.
The man driving the truck was not physically injured and has been taken to hospital for mandatory testing.
Officers from the Campbelltown City Police Area Command set up a crime scene which will be examined by the Crash Investigation Unit.
A report will be prepared for the information of the Coroner.
Anyone with information or dashcam footage is urged to call police or Crime Stoppers on 1800 333 000.