Eight fire engines and around 60 firefighters tackled a fire in a derelict pub on St James's Road in Croydon.
The whole of the second floor and the roof of the building were destroyed by fire, resulting in a roof collapse. There were no reports of any injuries.
One of the Brigade's 32-metre turntable ladders was used as a water tower to tackle the fire from above.
The Brigade's 999 Control Officers took 10 calls to the blaze.
The Brigade was called at 0544 and the fire was under control by 0835. Fire crews from Woodside, Croydon, Forest Hill and surrounding fire stations were at the scene.
The cause of the fire is under investigation.