The London Ambulance Service (LAS) dispatched police to Latchmere Road at 3.26 a.m. on Saturday, July 16, after receiving reports of a Mini Cooper on its roof.
Detectives believe no other vehicles were involved in this collision at this early stage of the investigation.
Officers were present, as were the London Ambulance Service and the London Fire Brigade.
Despite the efforts of emergency personnel, two passengers, a man and a woman, were declared dead at the scene.
The driver and another passenger are still hospitalised, but their injuries are not life-threatening.
The driver, a 22-year-old woman, was arrested and charged with causing death by dangerous driving.
As the investigation continues, extensive road closures remain in effect.
Detectives are interested in hearing from anyone who witnessed the collision or has dashcam footage of the incident.
Anyone with information should contact the Serious Collision Investigation Unit at 020 8991 9555 and reference 1112/16July.