Four fire engines and around 25 firefighters attended flooding on the North Circular in Brent.
The carriageway was flooded to a depth of around half a metre after a water main burst. Firefighters rescued eight people who were trapped in their vehicles due to the depth of the water. There were no reports of any injuries.
The Brigade was called at 1537 and the incident was under control by 1926. Fire crews from Hendon, Willesden and West Hampstead fire stations attended the scene.