Police are appealing for witnesses as a young woman fights for her life in hospital.
Officers were called to Epping Road at about 6.15am this morning after a collision between two cars.
A female in her 20s from the Chigwell area received life-threatening injuries and was taken to the Royal London Hospital.
A man and woman from Harlow suffered serious but not life-threatening injuries and were both taken to Princess Alexandra Hospital.
The man was later transferred to Addenbrooke’s Hospital, Cambridgeshire.
The collision happened between Epping and Crown Hill. The cars involved were a white Fiat 500 and a red Hyundai 110.
The road was closed until about 11.30am until the vehicles were recovered and initial police investigations were completed.
Any witnesses who have not yet spoken to police, or anyone with information about events leading to the collision, should contact the investigating officer Pc Dave Gorbutt at the Essex Police Serious Collision Investigation Unit on 101 or email firstname.lastname@example.org