A woman has been arrested after two sets of twin boys, aged three and four, died in a devastating house fire after being left home alone in south London.
The 27-year-old has been held on suspicion of child neglect, the Metropolitan Police said.
He wrote: “I am devastated to say that the horrendous house fire that took place in Sutton last night leading to four children loosing (sic) their life’s (sic) were my amazing smart and beautiful grandsons.
“(They were) taken too soon they will always be in our hearts and thoughts.
“Boys I love you forever. Grandad xxx”
Chief Superintendent Dave Stringer, borough commander for Croydon, Bromley and Sutton Police, confirmed that the children were related.
He told reporters at the scene on Friday afternoon: “There was nobody else inside the property at the time of the fire.”
He said detectives, the Met and the London Fire Brigade are investigating the cause of the blaze.
The woman arrested on Thursday night on suspicion of child neglect remains in police custody, the police chief said.
Police officers and forensics teams were seen going in and out of the house, where the once-white facade was blackened.
A blue police tent was pitched outside the property on the residential suburban street.
The chief superintendent said: “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.”
Fire crews were called to a mid-terrace house on Collingwood Road, Sutton, shortly before 7pm on Thursday and found a “very well-developed” blaze, with the four boys inside, said Richard Mills, deputy commissioner of the London Fire Brigade.
Mr Mills said firefighters in breathing apparatus entered the home, removed the four children and gave them CPR.
They were then taken to two south London hospitals where they were pronounced dead.
The fire was under control by 8.36pm.
Speaking of the firefighters involved, Mr Mills said: “Entering a building and rescuing life is always a very difficult place to be.
“The age of the children, the fact they are so young, will have a profound impact on them.”
Crews who attended are receiving counselling, he added.
Mourners laid floral tributes, candles and teddy bears outside the police cordon throughout the day on Friday, with one card reading: “Sleep well little angels.”
The four boys were “so well behaved” and “polite”, according to a woman who works at a nearby shop.
The 24-year-old, who did not want to give her name, said the boys often came to her shop with their mother.
She said: “They were always all holding hands, they were so well behaved, so polite.”
The Rev Frances Arnold, priest of the local St Nicholas church, said: “It’s a great shock and tragic loss of life, young children, and so we’ll continue to offer our prayers for the family, the friends, the community here, the emergency services”.
Matt Gray, manager of Sutton United football club, added yellow-and-black team scarves to the pile of tributes at the scene.
He said it was “such a tragic event to happen on our doorstep” and “a huge shock and obviously very devastating”.
Westbourne Primary School in Sutton said it was “devastated” by the deaths of the children, two of whom were pupils there.
In a statement, the school said: “Westbourne Primary 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 heartbreaking event.
“We will continue to support the children, the staff, the families and the community through these very difficult times.”
Home Secretary Priti Patel tweeted: “My thoughts and prayers are with the families and loved ones of the four young children who tragically lost their lives in the fire in Sutton yesterday.
“I am being kept updated by the emergency services and I would like to thank them for their work in such sad circumstances.”