Four fire engines and around 25 firefighters were called to a fire on the top floor of a block of flats on Loddiges Road in Hackney.
Most of a three room flat on the sixth floor of a block of flats was destroyed by fire.
One woman left before the Brigade arrived on scene and was taken to hospital by London Ambulance Service suffering from smoke inhalation.
The Brigade's 999 Control Officers were called at 1521 and the incident was over by 1641. Fire crews from Homerton, Stoke Newington, Bethnal Green and Shoreditch fire stations were in attendance.
The cause of the fire was accidental and due to the use of an angle grinder too close to combustible materials.