Officers are appealing for witnesses and any dashcam footage following a fatal collision in Hillingdon Village.
Emergency services were called at 9:21 yesterday evening (13 November) to reports of an overturned silver BMW M5.
The 42-year-old female passenger in the car was pronounced dead at the scene. Her next of kin have been informed.
The 34-year-old driver of the car has been taken to a central London hospital. His condition is not believed to be life-threatening.
Enquiries to establish the cause of the collision continue, however it is believed the BMW may have collided with railings before overturning. There has been no arrest at this stage.
Police are urging witnesses or anyone with dashcam footage that may have captured the incident to call the Serious Collision Investigation Unit (Team 3) on 020 8246 9820 quoting CAD 7283/13nov.