Five fire crews including around 35 firefighters rushed to Harrow in the early hours to tackle a flat fire on Alexandra Avenue this morning.
London Fire Brigade said that part of a four-roomed flat on the second floor of a residential block was damaged by fire.
A small part of the roof was also damaged by the blaze.
Seven people, including four children, left the building before the Brigade arrived at Alexandra Avenue and were treated on scene by London Ambulance Service crews.
The fire is believed to have been accidental and caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: “We’d rather you didn’t smoke at all, but if you are a smoker, it’s absolutely vital you ensure your cigarette is completely out when you’ve finished smoking it.
“If you don’t, you risk causing a fire which could not only destroy properties but also cost you your life.”
The Brigade was called at 2:27am and the fire was under control by 4:47am.
Fire crews from Northolt, Harrow, Wembley and Ruislip fire stations attended the scene.
