Six fire engines and around 40 firefighters were called to a fire in a four storey block of flats on Lichfield Road in Hounslow.
A first floor flat and the roof of the building were destroyed by fire. Three other flats were also damaged by fire.
Firefighters wearing breathing apparatus evacuated sixteen people from the building.
The Brigade was called at 0134 and had the fire under control by 0524. Fire crews from Feltham, Heston, Twickenham and other surrounding fire stations attended the scene.
The cause of the fire is under investigation.