Two fire engines and 10 firefighters and officers were called to a fire at a house converted into flats in Whitley Road, Tottenham on Sunday.
The stairwell within the block was damaged by fire.
Two adults and a child were assisted from the first floor by ladder by firefighters and one person was led to safety from a ground floor flat by breathing apparatus crews.
The Brigade was called at 0112 and the fire was under control at 0151. Fire crews from Tottenham fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police Service.