An 11-year-old girl was killed while waiting with her mother at a bus stop when a pensioner's car veered on to the pavement and crashed into them.
Officers were called to The Common in Stanmore, following reports that a vehicle had collided with two pedestrians and a stationary bus.
Emergency services pronounced the girl dead at the scene, while her 46-year-old mother was taken to hospital and remains in a critical condition.
Firemen cut the 69-year-old driver from her Ford Fiesta and she was taken to hospital with minor injuries. No arrests have been made.
Police said they were awaiting formal identification ahead of a post-mortem due to take place tomorrow at Northwick Park Hospital.An inquest is expected to open at Barnet Coroner's Court "in due course", Scotland Yard said.
More top news
Residents from Grenfell Tower who were being temporarily housed in a Kensington hotel say they were told to leave with just hours notice
Members of the London community have rallied round to offer their help to residents of the evacuated Chalcots estate in Camden.
Evacuated residents have expressed anger and confusion at unexpectedly being told they had to leave .