A 27-year-old woman has been arrested on suspicion of child neglect after two sets of twins died in a house fire.
The boys, named locally as Kyson, Bryson, Leyton and Logan, died when an “intense” fire broke out at their home in Collingwood Road, Sutton, last night just before 7pm.
The twins, all boys aged three and four, were given emergency treatment and rushed to hospital where they were pronounced dead.
The cause of the blaze is being investigated.
Mr Mills said when firefighters arrived at the house the blaze was “very well-developed”.
“Firstly, I’d like to acknowledge the terrible tragedy that took place last night and our thoughts remain with the family, friends and community of the sad loss of life of four young children,” he said.
Asked if anyone else was in the home, he said: “On arrival there were four children in the house.”
London Fire Commissioner Andy Roe said the fire “has left everyone numb with profound sadness”.
“Fire crews arrived quickly and located the children inside the property,” he said.
“They were brought out of the house and given immediate emergency care. The welfare of our staff involved in this incident is very important to us and all of them will be offered counselling as a priority.”
Flowers were laid at the scene on Friday with a message on one bouquet reading: “To Kyson Bryson Leyton + Logan. Sleep well. Love Grandad.”
Grandfather Jason Hoath shared a heart-breaking tribute to his grandsons on Facebook next to a photo of them.
He wrote: “I am devastated to say that the horrendous house fire that took place in Sutton last night leading to four children losing their lives were my amazing, smart and beautiful grandsons.
“Kyson and Bryson, aged four, and Leyton and Logan, aged three, were taken too soon they will always be in our hearts and thoughts.
“Boys, I love you forever. Grandad xxx”
Eight fire engines and around 60 firefighters were called to the blaze. The fire brigade said the first crews on the scene were faced with an intense blaze throughout the whole of the ground floor.
A spokesperson for London Fire Brigade said: “Firefighters in breathing apparatus entered the mid-terrace house and brought four young children out of the property.
“They were given immediate CPR by firefighters at the scene, who continued to administer treatment to assist London Ambulance Service crews on arrival.
“All four children were removed to hospital where, tragically and despite the efforts of all involved, they were pronounced deceased.”
The fire was under control by 8.30pm.
Neighbours were heard screaming as flames shot up from the ground floor of the terraced house.
Outside the property scorched parked cars could be seen and the whole front of the house was charred.
One neighbour said: “We saw the flames and just couldn’t believe our eyes. Those poor kids. We were all screaming and calling the emergency services.”
A woman who worked at a nearby shop said the four boys were “so well behaved” and “polite” when they came in with their mother.
She said: “They were always all holding hands, they were so well behaved, so polite.”
Westbourne Primary School in Sutton said it was “devastated” by the deaths of the four boys – two of whom were pupils there – in a house fire.
In a statement, it said: “The school and its entire community are devastated at the news of the tragic loss of the four children; our hearts, thoughts and prayers are with the family and anyone else affected by this heart-breaking event.
“We will continue to support the children, the staff, the families and the community through these very difficult times.”
The Metropolitan Police said next of kin were aware and would be provided with specialist support.
Police said no arrests had been made.
Chief Superintendent Dave Stringer, who is responsible for policing in Sutton, Croydon and Bromley, said on Friday afternoon: “The thoughts of everyone at the Metropolitan Police are with the family and friends of the four young boys who lost their lives in this tragic incident.
"We know it will have come as a great shock to the local community and as part of that community, we are here to offer whatever support we can.
"At 7pm last night, we were called to reports of a fire in a residential property.
"Officers responded to the incident alongside colleagues from the London Fire Brigade and London Ambulance Service.
"As has been confirmed, four boys who were inside – two aged three and two aged four – were brought out but sadly died. They were all related.
"There was nobody else inside the property at the time of the fire.
"Our London Fire Brigade colleagues acted heroically in recovering the children and I want to pay particular tribute to them.
"I know this incident will have a lasting impact on them and on the police officers and paramedics who were involved. We will make sure they get the support they need.
"Local detectives will be investigating this incident and that work is already under way.
"We will be working with colleagues from the London Fire Brigade to determine what caused the fire and to investigate any other relevant matters.
"As part of that investigation, a 27-year-old woman was arrested last night on suspicion of child neglect. She remains in police custody.
"We have also held discussions with partners in the local authority and the wider community today and will continue to do so to ensure that together we can support local residents as they come to terms with this tragic loss.”