Neighbours said it sounded ‘like a bomb had gone off’ on Galpin’s Road in Thornton Heath, near Croydon, just after 7am this morning, as 40 firefighters and six fire engines quickly rushed to the scene.
Three people have been hospitalised with potentially life-threatening injuries and the fire brigade confirmed their urban search and rescue crews are searching for one more missing person.
Two neighbours, Kutoya Kukanda, 50, and Delroy Simms, 62, who have been called have been called ‘heroes’ for rescuing three children from the rubble at around 7am, said they feared a young girl was still trapped inside.
Mr Simms, dressed in his pyjamas by the cordon, said the explosion was like an earthquake and knew what it was because ‘that gas was smelling all week, really strong’.
He said that Mr Kukanda passed children out to him as bricks were still falling from the structure.
Videos and pictures shows the house completely reduced to rubble, planks of wood strewn about, and neighbours standing shocked outside in their dressing gowns.
Surrounding properties and vehicles are seriously damaged with tiles and bricks from the destroyed housing laying on top of them.
Around 40 properties have been evacuated as a precaution and a 50-metre cordon is in place.
One man was treated for burn injuries at the scene and witnesses said other people including a child were stretchered away, Thornton Heath Chronicle reported.
A young girl was also seen stood outside with a blanket being treated for burns, as three people are currently in hospital with potentially life-threatening injuries.
London Fire Brigade (LFB) said four people have been rescued and are asking people to avoid the area.
On the road where properties sell for around £430,000, the explosion launched a mass of rubble which seriously damaged houses either side of the blast and across the road.
Neighbours said they had reported a strong gas smell two weeks ago and others said they had been feeling dizzy and sick over the last two days.
One person said they were still able to smell gas after the blast which shattered windows and severely damaged neighbouring properties as other houses in the area were also evacuated.
A mother was crying in the street for her son as his bedroom was opposite the completely destroyed house, said one local.
The 25-year-old woman told MyLondon: ‘His mum was out on the street crying ‘My boy, my boy’.
‘They took him to hospital and we’ve heard since that he’s ok.’
She added that a ‘little girl’ and her dad escaped the destroyed house, and that the mum was rescued afterwards.
One resident, who lives on nearby Carisbrooke Road, said: ‘I heard the explosion at 7am, it was just the biggest bang you’ll ever hear.
‘So I went down the road to see what happened this morning and the whole house is gone, people living nearby said all their windows shook.
‘There was police, fire engines, a helicopter going around overhead.
There’s not actually a fire from what I saw but you can still really smell gas, even two roads away where I am.
They’re evacuating people from the houses nearby as they’re worried about another explosion.
‘There was a little girl of about 10 or 11 stood outside with a blanket bless her, god knows how she got out of that but she’s being treated for burns.
‘They were saying her older brother was still inside but he later got taken out OK I think.’
Dominic Francis, 41, and his partner heard a loud bang this morning, he said: ‘It is the third or fourth house explosion in the UK recently.
‘Something is wrong, I am worried it will happen to us.’
One Facebook user said: ‘I heard it whilst getting ready for work and thought it sounded like an explosion but was hoping I was wrong and that it was at a building site or something.’
Another added: ‘That was one loud bang thought a bomb had gone off’.
A London Ambulance Service spokesperson said: ‘We have treated four patients at an incident in Galpins Road, Thornton heath. One was discharged on scene and three others were taken to hospital.
‘We remain on scene with our emergency service colleagues.’
A London Fire Brigade spokesperson said in a statement: ‘Six fire engines and around 40 firefighters have been called to a fire and explosion on Galpin’s Road in Thornton Heath.
‘A terraced house has collapsed following an explosion.
‘The Brigade’s 999 Control Officers have taken 13 calls to the incident.
‘The Brigade was called at 0708. Fire crews from Norbury, Mitcham, West Norwood, Woodside and surrounding fire stations attended the scene.
‘The cause of the fire and explosion is not known at this time.’
The Metropolitan Police confirmed officers are at the scene. A statement on Twitter said: ‘Officers are at the scene in Galpin’s Road as part of the emergency services response to this incident. Please follow @LondonFire for updates.’
London Ambulance Service said it is also responding to the incident.