Eight fire engines and around 60 firefighters tackled a flat fire on St Lukes Mews on the Isle of Dogs.
A four-roomed flat on the third floor of a residential block was destroyed by fire and part of a flat on the fourth floor was also damaged by the blaze. Around 25 people left the building before the Brigade arrived, whilst others remained in their unaffected flats. There were no reports of any injuries.
The Brigade's 999 Control Officers took 55 calls to the blaze.
Station Commander Andy McKay, who was at the scene, said: "Firefighters worked quickly to bring the fire under control.
"West Ferry Road was closed between Byng Street and Marsh Wall whilst crews made the scene safe. This caused heavy traffic, so we urged people to avoid the local area.
"Our Control Officers gave vital fire survival guidance to those inside the building on how to stay safe whilst firefighters brought the fire under control."
The Brigade was called at 1901 and the fire was under control by 2011. Fire crews from Shadwell, Whitechapel, Bethnal Green, Dowgate, Dockhead and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.