Eight fire engines and 58 firefighters and officers were called to a fire in a flat in Leather Gardens, Stratford.
A flat on the 17th floor was destroyed by fire. There were no reports of any injuries. Around 100 people left the building before the arrival of the Brigade.
The Brigade's 999 Control Officers took 26 calls to the fire.
The Brigade was called at 0122 and the fire was under control at 0252. Fire engines from Stratford, Plaistow, Leyton, East Ham, Bethnal Green and surrounding fire stations attended the scene.
The Brigade's fire investigators believe the fire was accidental and was caused by a fault in a boiler.