Eight fire engines and around 60 firefighters tackled a fire at a shop with flats above on Southwark Park Road in Bermondsey.
The ground-floor shop was destroyed and a small part of a first-floor flat was damaged by fire. Firefighters wearing breathing apparatus led a child to safety from a third-floor flat using a fire escape hood. There were no reports of any injuries.
London firefighters were among the first in the UK to carry fire escape hoods when they were introduced in 2018 as part of improvements following the Grenfell Tower fire. The hoods provide members of the public with up to 15 minutes protection from four of the main fire gases (carbon monoxide, hydrogen cyanide, hydrogen chloride and acrolein) and can be worn by conscious or unconscious people. If more than 15 minutes protection is required then another hood can be given to each wearer. They do not provide oxygen but temporarily filter toxic smoke to make breathing easier.
Station Commander Tony Perks, who was at the scene, said: "Initial crews faced a very intense fire on arrival and worked swiftly to bring it under control and ensure residents in flats above the shop were safe.
"There are road closures in place, which are expected to remain for a number of hours this evening, and we recommend people continue to avoid the area."
The fire is believed to have been accidental and caused by the failure of a lithium-ion battery.
A London Fire Brigade spokesperson said: “Lithium batteries are susceptible to failure if incorrect chargers are used, so it’s important to always use the correct charger for the product and buy an official one from a reputable seller.
“You should unplug your charger when you have finished using it and we would advise not to leave it unattended or charging while people are asleep.
“Batteries can present a fire risk if they’re over-charged, short circuited, submerged in water or damaged, so it’s really important to protect them against being damaged too.
“Try to ensure they are not getting knocked around while in use or while being carried as this can increase the chance of damage to cells.”
The Brigade's Control Officers took the first of four calls to the fire at 1755 and sent fire crews from Dockhead, Old Kent Road, Deptford, New Cross, Peckham, Dowgate, Whitechapel and surrounding fire stations to the scene. The fire was under control by 1908.