Police were called to at 8.49pm on Monday, 30 November to reports of a Citroen Dispatch van in collision with a silver-coloured Vauxhall Corsa on the A406 at Pinkham Way, N11.
Officers and London Ambulance Service [LAS] attended.
The Vauxhall Corsa was stationary in the slow lane due to a flat tyre. Inside the car were one woman and four children.
All the occupants of both vehicles were taken to the hospital. A four-year-old girl from the Corsa suffered a non-life-threatening, but potentially life-changing head injury. She remains in hospital undergoing treatment.
The others, including the driver of the Citroen, did not sustain serious injuries.
The driver of the van, a 39-year-old man was arrested on suspicion of drink-driving, and causing serious personal injury by dangerous driving. He was taken to hospital as a precaution before being taken to a north London police station where he was subsequently released under investigation.
Detective Constable Maciej Mielcarek of the Met’s Roads and Transport Policing Command said: “I am interested in speaking to anyone who witnessed this collision or who may have captured any part of it on dash-cam.
“I know that a number of good Samaritans stopped at the scene to help, for which we are very grateful, but I also need to speak with those people in order to piece together the sequence of events.
“A child has been seriously injured and it is important that we establish the circumstances surrounding the incident. If you saw anything before, during or immediately following this collision please do get in touch.”
Anyone with information or footage should call police on the dedicated witness line 020 8246 9820, call 101 or Tweet @MetCC quoting 6785/30NOV20.