Six fire engines and around 40 firefighters were called to a fire at a derelict residential building on Southend Road in Beckenham.
Firefighters tackled a fire at the three-storey building where the roof and second floor were completely destroyed by the fire, part of the first floor was also damaged. There were no reports of any injuries.
Fire crews remained at the scene for several hours to dampen down the area. The Brigade’s Control Office took 21 calls about the fire.
The cause of the fire is believed to have involved a firework.
A London Fire Brigade spokesperson said: "Fireworks can be spectacular, but they are explosives and can cause serious injury if handled irresponsibly.
"We encourage people to attend organised fireworks displays instead of using fireworks privately, but if you do choose to use fireworks, make sure you have enough space, buy them from a reputable, licensed seller and always look for a CE mark to make sure they’re safe. Never drink alcohol and set off fireworks and don’t throw fireworks or return to a firework once it has been lit.
“Remember that fireworks are explosives, and as such should be treated with respect and only used in accordance with the manufacturer’s instructions and the Firework Code.”
The Brigade was called at 1947 and the fire was under control by 2200. Fire crews from Forest Hill, Bromley, Woodside, Lewisham, Beckenham and Lee Green fire stations attended the scene.