Detectives are appealing for dashcam footage following the death of a man whose car ploughed into a tree in Harrow.
The 28-year old was driving a grey Volkswagen along Preston road when the incident happened at around 1.15am on 25 April.
The airbags in the car had activated and members of the public got the driver out of the vehicle.
He was conscious, breathing and answering questions.
Police, London Ambulance Service and London Fire Brigade were scrambled to the scene.
The driver was taken by ambulance to hospital where his injuries were initially classified as not life threatening.
But he died in hospital on 29 April.
A police spokesman said: “We are keen to hear from anyone who witnessed or has footage of the collision.”
Anyone with information is asked to call Serious Collision Investigation Unit at Alperton on 020 8246 9820.
Witnesses can also call the police on 101 quoting CAD 301/25APR23 or Crimestoppers anonymously on 0800 555 111 or visit Crimestoppers-uk.org.
