Eight fire engines were called to a fire at a car workshop on Thurlow Gardens, Wembley.
A single storey car workshop was completely destroyed by fire and three adjoining units were also damaged in the blaze.
The Brigade received the first of over 30 calls reporting the fire at 1709. Control Officers mobilised crews from Park Royal, Willesden, Northolt and surrounding fire stations to the scene. Firefighters had the incident under control by 1823.
The cause was accidental and believed to be due to hot cutting works which ignited combustible items.