Four fire engines and 21 firefighters and officers were called to a fire at a house converted into flats on the North Circular Road in Neasden this morning.
Half of the ground and part of the first floor of the terraced property was damaged by fire.
Two people left the property before the Brigade arrived. They were taken to hospital by the London Ambulance Service crews.
One person was led to safety, uninjured, by firefighters wearing breathing apparatus. Four adults and two children left an adjacent property before the arrival of the Brigade.
The Brigade was called at 0801 and the fire was under control at 0929. Fire crews from Willesden, Hendon and West Hampstead fire stations attended the scene.
The cause of the fire is under investigation.