Two fire engines were called to a fire and a possible gas explosion at a block of flats in Sheen Gate Gardens, East Sheen this morning.
Part of a ground floor flat was damaged.
A man left the property before the arrival of the Brigade and was treated at the scene by London Ambulance Service before being taken to hospital.
Another three people left a first floor flat before the arrival of the Brigade and a further10 people were evacuated from neighbouring properties.
The Brigade was called at 0618 and the fire was under control at 0824. Fire crews from Richmond and Chiswick fire stations attended the scene.
The cause of the fire is under investigation by the Brigade, the Metropolitan Police Service and Health and Safety Executive.