Appin Road has been reopened in both directions after a serious crash involving a car and truck earlier this morning.
One person was believed to be trapped in the car and the ambulance rescue helicopter was sent to the scene.
The NSW Crash Investigation Unit has been deployed to investigate the cause of the accident.
Due to the serious nature of the crash, Appin Road is expected to be closed for several hours.
Motorists are advised to avoid the area and use Picton Road, Macarthur Road and Wilton Road as alternative routes.