A man has died after a single-vehicle crash at Mulgoa.
Emergency services were called to Fairlight Road about 5pm today, after reports a car had left the road and rolled.
The front seat passenger, a man believed to be aged in his 20s, was taken to Westmead Hospital in a critical condition but later died.
The driver has been taken to Westmead Hospital to undergo mandatory blood and urine testing. He is also being treated for shock.
The two backseat passengers were treated for non-life-threatening injuries.
Officers from Nepean Police Area Command attended the scene.
Inquiries into the circumstances leading up to the crash will be conducted by the Crash Investigation Unit.