Firefighters are reminding people about the importance of having working smoke alarms after a fire at a house on Little Dimmocks in Tooting.
Most of the ground floor of the terraced house was damaged by fire.
Watch Manager Kirk Williams, who was at the scene, said: "Thankfully, the house was empty at the time of the fire. The property didn't have any smoke alarms and neighbours were only alerted to the fire when because they heard crackling noises.
"This incident shows just how important it is to have working smoke alarms fitted on every level of your home.
“Smoke alarms give the earliest possible warning when a fire starts and we would urge everyone to make sure they have one fitted in every room where a fire can start except kitchens or bathrooms where heat alarms are more appropriate.”
Four people self evacuated from neighbouring properties. There were no reports of any injuries.
The Brigade was called at 0127 and the fire was under control at 0252. Four fire engines and around 25 firefighters from Tooting, Clapham and Battersea fire stations attended the scene.
The fire is believed to have been caused by resistive heating within an extension lead.