A woman died and three people were airlifted to Canberra Hospital after a car crash on the Hume Highway near Yass.
NSW Police were called to the crash about 1km south of the Lachlan Valley Way turn-off at about 2.15pm Thursday.
On arrival, officers found a four-wheel-drive had rolled and a female occupant of the car had died at the scene.
The male driver and a man and another woman who were also in the car have been airlifted to Canberra for treatment.
Motorists have been warned to take care in the area, with diversions in place on the Hume Highway northbound lanes between Bowning and Yass.
Police from the southern region crash investigation unit will attend the scene and investigate.