Six fire engines and around 40 firefighters tackled a fire at a house on Penrith Close in Wandsworth.
Half of the roof of a mid terraced house was damaged by the fire. The first floor was destroyed by the fire. A man and a woman left the building before the Brigade arrived. Both people were treated on scene by London Ambulance Service and the man was taken to hospital.
The Brigade was called at 0146 and the fire was under control by 0326. Crews from Wandsworth, Fulham, Battersea and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.