Four fire engines and around 25 firefighters tackled a fire at a block of flats on High Street in Whitechapel.
A stairwell running from the fourth floor to the fifth floor of the six-storey building was destroyed by fire. There were no reports of any injuries.
Road closures were put in place to allow crews to work safely.
The Brigade's 999 Control Officers received 14 calls about the fire.
The Brigade was called at 0616 and the fire was under control by 0711. Fire engines from Whitechapel, Shadwell, Old Kent Road and Bethnal Green fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police.