AN investigation was under way last night after a woman was left fighting for her life when her car collided head-on with an ambulance answering a 999 call.

AN investigation was under way last night after a woman was left fighting for her life when her car collided head-on with an ambulance answering a 999 call.

The woman, from Harwich, was airlifted to hospital after the horrific smash and her three-year-old son was last night also being treated in hospital in a “serious but stable” condition.

The accident happened at midday on Saturday on the A120 road at Wix, as the ambulance was travelling to Harwich on a 999 emergency call.

The 30-year-old was driving towards Colchester with her son when her blue Peugeot 106 collided with the ambulance, which was not carrying any patients at the time.

She suffered head, pelvic and leg injuries and was taken by air ambulance to Colchester General Hospital and later transferred to Oldchurch Hospital in Romford, where she is in a critical condition in the intensive care unit.

Her son was taken to the same hospital by land ambulance and was later transferred to Addenbrooke's Hospital, Cambridge, where he is said to be in a stable condition.

After the boy and his mother were treated, the ambulance crew involved in the crash were then taken to hospital suffering from minor injuries.

Both the car and the ambulance suffered considerable damage in the accident, which left the ambulance in a field and the road closed for five hours.

Three fire crews from Dovercourt, Manningtree and Colchester were sent to the scene, and used cutting equipment to free the woman and her son from the car.

Assistant Divisional officer Kevin Thornicroft, who was in charge of the incident, said: “The front passenger side of the car took the full impact of the crash and had the little boy been bigger, he would probably have died in the accident.

“The fact that he was so small meant that he didn't take the full impact. Although it appeared the casualties were trapped when we arrived, there was minimal damage to the driver's side and we were able to get the victims out through the doors.”

Paul Leaman, the ambulance service's chief operating officer in Essex, said: “The ambulance crew quickly assessed their injuries and started treating them while they waited for back up to arrive.

“Our thoughts are with all of those involved in this crash at what is a very difficult time.

“A full investigation has been launched by the service's own crash investigation team, in co-operation with officers from Essex Police. It is too early to give any indications as to what happened.”

Police are appealing for witnesses to the crash, in particular the driver and passenger of a silver Volkswagen Golf which stopped at the scene.

The occupants spoke to officers at the roadside, but police are keen to speak again to the couple, thought to be in their late 30s.

Anyone with information about the incident can contact Stanway Road Policing Unit on 01206 762512.