Three teenagers have been arrested in connection with a crash which left a woman with "life-threatening" injuries.
Essex Police said it was called to Creeksea Ferry Road in Canewdon at about 01:50 BST where a black Ford Fiesta had "come to stop in a ditch".
An 18-year-old woman remains in hospital in a life-threatening condition, the force said.
Two boys aged 17 and an 17-year-old girl were arrested after being taken to hospital.
All three have been arrested on suspicion of causing serious injury by dangerous driving.
The force said officers were trying to locate a fifth person who was believed to be in the vehicle but left the scene after the collision.
The road remains closed and officers have asked anyone with information, CCTV or dashcam footage to contact them on 101.