Five fire engines and around 35 firefighters were called to a fire at a block of flats under construction on Prestons Road in Canary Wharf.
Part of a five-roomed flat on the 35th floor of a 36-storey block was damaged by the fire. One man suffering smoke inhalation left the building before the Brigade arrived. He was treated on scene by London Ambulance Service crews. A further 400 staff were evacuated by on-site personnel as a precaution.
The Brigade was called at 1504 and the fire was under control by 1604. Fire crews from Millwall, Poplar, Plaistow and Shadwell fire stations attended
The cause of the fire is under investigation.