Police are appealing for witnesses after three men were injured in a collision between an ambulance and a car in Golders Green on Saturday morning.
The accident happened shortly before 8.10am on the North Circular Road near the junction with Connaught Drive.
The driver of the dark blue Peugeot 307 was treated at the scene before being taken by air ambulance to an East London hospital.
Two male passengers were also taken to hospital by ambulance, but were later discharged.
The ambulance crew were treated at the scene for minor injuries.
The driver remains in hospital in a serious but stable condition.
No arrests have been made.
Any witnesses are asked to contact the Serious Collision Investigation Unit at Alperton on 020 8991 9555 or Crimestoppers anonymously on 0800 555 111.
Detectives say they are keen to here from anyone who may have seen the Peugeot being driven westbound on the North Circular Road immediately before the collision.
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