Ten fire engines and around 70 firefighters were called to a fire at a mixed-use building on Laban Walk in Greenwich.
A decking area in a rooftop garden was destroyed by fire. Around 50 residents were evacuated as a precaution from the 9th 10th and 11th floors of the building. There were no reports of any injuries.
Station Commander Jeremy Davies, who was at the scene, said: "Firefighters worked incredibly hard to bring the incident under control as quickly as possible and ensure residents were safe.
"One of the Brigade's 64-metre turntable ladders was deployed to tackle flames from height, and also provide the Incident Commander with an aerial view to help develop tactics to bring the fire under control.
"Cordons were in place, so we encouraged people to avoid the area this morning."
The Brigade's Control Officers took the first of 25 calls to the fire at 0503 and sent crews from Deptford, Greenwich, New Cross, East Greenwich and surrounding fire stations to the scene. The fire was under control by 0557.
The fire is believed to have been accidental, most likely caused by a failure of the electrical lighting circuit on the roof terrace.