Four fire engines and around 25 firefighters tackled a flat fire on Westmoreland Drive in Sutton.
A composite cylinder, an external door and a window on a ground-floor balcony were damaged by fire. Firefighters cooled the cylinder to an ambient temperature as a precaution as some cylinders can explode when exposed to heat. A woman was assessed on scene and went to hospital.
The Brigade’s 999 Control Officers took 23 calls to the blaze.
The Brigade was called at 1935 and the fire was under control by 2038. Fire crews from Sutton, Wallington and Croydon fire stations attended the scene.
The cause of the fire is under investigation.