Four fire engines and around 25 firefighters tackled a fire on Forest Road in Walthamstow.
Most of a second-floor flat in a three-storey mixed-use building was destroyed by fire. Seven people left the flat before firefighters arrived. One person was taken to hospital by London Ambulance Service crews and a further two people were treated at the scene.
The fire is being treated as accidental and is believed to have been caused by the unsafe use of candles.
A London Fire Brigade spokesperson said: "Candles are one of the most common causes of fire. It’s really important that you never leave a candle unattended and keep them away from anything else that can easily catch alight.
"Firefighters recommend that you have a look at our online Home Fire Safety Checker to make sure there are no hidden hazards in your home.
"The online tool will ask you a series of questions that will help us work out the level of risk in your home, or the home of someone you care for. It only takes a few minutes to get tailored advice to keep yourself and loved ones safe from fire."
The Brigade's Control Officers received six calls about the fire. The Brigade was called at 0358 and the fire was extinguished by 0523. Crews from Walthamstow, Leyton and Woodford fire stations attended the scene. A 32 metre turntable ladder also attended and was used as an observation tower, providing the Incident Commander with a greater situational awareness of the incident.
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