The crash involving a car and a van was reported to emergency services at 11.40pm on November 6, 2025, on Ferny Hill, Barnet.
At the scene three teenage boys and a man in his 40s were located, all in need of medical assistance.
One of the three boys who had been in the car at the time of the incident died two days later on November 8.
A second boy has sustained life-changing injuries and has been discharged from hospital.
The third teenager and the driver of the van did not suffer serious injuries.
There have been no arrests and an investigation is ongoing to confirm the circumstances surrounding the crash.
Detective Constable Pauline Redmond said: “This was a serious collision, which resulted in the death of an 18-year-old boy.
“The Met is launching an investigation in order to establish exactly what happened, and hopefully bring a measure of comfort to the victim’s family, his friends and the survivors.
“As part of this, we are appealing for anyone who was in the area on the night of the incident to come forward.”
Anybody who witnessed the incident, or who has potentially relevant dashcam footage from the evening, should contact 101, quoting reference 9358/06NOV.
