Firefighters responded to a fire involving an electrical transformer and communication mast in Willesden Green.
Crews were able to bring the fire under control once UK Power Networks were able to isolate the supply to the transformer.
A neighbouring supermarket was evacuated and closed as a precaution whilst crews responded. The fire produced a significant amount of smoke and residents in the immediate area were advised to keep doors and windows closed where possible.
The Brigade was first called about the fire at 1718. Crews from Willesden and West Hampstead fire stations attended the scene.
The cause of the fire is now under investigation by the Brigade's specialist Fire Investigation Officers.