Six fire engines and around 40 firefighters were called to a burst water main at a block of flats in Hindmarsh Close, Whitechapel.
A water main on the eighth floor of the building burst, with flooding occurring on all floors from eighth to ground floor level.
Crews isolated the water supply and removed residue water on the affected floors.
The Brigade was called at 0604 and the incident was over for firefighters at 0913. Fire crews from Whitechapel, Dowgate, Dockhead, Shoreditch, Bethnal Green and Old Kent Road fire stations attended the scene.