Six fire engines and around 40 firefighters were called to a fire at a disused building on Haven Green in Ealing.
The building consisted of four floors with a fitness studio, squash courts and two flats above the squash court. A four-roomed flat on the third floor was destroyed by the fire and part of a second flat on the third floor of the building was also damaged by the blaze. One man left the scene before firefighters arrived and a second man was rescued by firefighters.
The Brigade was called at 0608 and the fire was under control by 0758. Fire crews from Ealing, Acton, Park Royal, Chiswick and Southall fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.