Four fire engines and around 25 firefighters tackled a fire on High Street, Willesden.
The ground floor storeroom of a retail warehouse was destroyed by the fire. A small part of an external transformer on the first floor was also damaged by the fire. There are no reports of any injuries.
Control Officers took the first of 21 calls at 0919 (10/10) and mobilised crews from Park Royal, Willesden and North Kensington fire stations to the scene. The fire was extinguished by 1048.
The cause of the fire has been recorded as undetermined.