Driver seriously injured after NSW crash

Two men have been seriously injured after a car apparently rolled during a crash northwest of Sydney.

Police say the the 21-year-old driver lost control of the car on Springwood Road at Yarramundi just before midnight on Thursday.

He was taken to Westmead Hospital, along with his 19-year-old passenger.

The driver suffered serious head injuries and remains in a serious, but stable condition, while the younger man is in a stable condition.

Police have appealed for witnesses.