Two fire engines and around 10 firefighters were called to an automatic fire alarm sounding at a sheltered accommodation block on Duckett Street in Stepney.
The alarm was raised by a small cooking fire that self-extinguished before crews arrived.
Sadly, one man was found dead in a ground floor flat at the scene.
The Brigade was called at 1609 and the incident was over for firefighters by 1722. Fire crews from Bethnal Green and Shadwell fire stations attended the scene.
The incident is under investigation by the Brigade and the Metropolitan Police Service.