A house fire that claimed the lives of two young children is likely to have been caused by an electrical fault in a first-floor bedroom, investigators have said.

Wisbech Standard: Floral tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireFloral tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

Emergency services were called to the blaze at the three-storey house in Buttercup Avenue in Eynesbury, St Neots, on Thursday morning.

Cambridgeshire Police said it is believed the fire broke out at around 7am.

Wisbech Standard: People leave tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WirePeople leave tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

A three-year-old boy and a seven-year-old girl were pronounced dead at the scene.

Their 35-year-old mother was taken to hospital with life-changing injuries after she leapt from a second-floor window to escape the inferno.

Wisbech Standard: Floral tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireFloral tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

Her partner, a 46-year-old man, suffered minor injuries.

Police said in a statement: “An investigation into the fire has concluded the most probable cause was an electrical fault in a first-floor bedroom at the property.

Wisbech Standard: Floral tributes are left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireFloral tributes are left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“There are no suspicious circumstances and a file is in the process of being handed to the coroner where police involvement will end.”

Floral tributes and soft toys have been left on a verge near the house.

Wisbech Standard: Emergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireEmergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

A message left with a teddy bear read: “We have no words. So heartbroken. Hope you are all in a better place. XXX.”

Windows on the terraced home’s second and third floors are completely burnt-out, with the rooms inside blackened and guttering melted away.

Wisbech Standard: Tributes left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireTributes left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

The house is on a modern estate near St Neots, with many homes decorated for Christmas - including a festive wreath on one immediate neighbour’s door.

It is understood the electrical fault was not caused by Christmas lights or decorations.

Wisbech Standard: A woman places a teddy bear with other tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireA woman places a teddy bear with other tributes at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

Neighbour Charles Cooper, 30, said: “The flames went up fairly swiftly.

“By the time my wife and I woke up the firefighters had already arrived.

Wisbech Standard: Emergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireEmergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“It took a good three or four hours before the smoke abated.

“The flames were coming out of the top window.”

Wisbech Standard: Emergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireEmergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

He said he did not know the family to speak to but “we would give them a wave”.

He added: “I’ve seen the children playing in the garden.

Wisbech Standard: Soft toy tributes left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireSoft toy tributes left at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“Everyone’s perfectly polite and pleasant but it’s not the sort of place we all get together on a regular basis.”

Neighbour Peter Kellythorn, 40, said there was a smell “like something might be smouldering” when he awoke on Thursday.

Wisbech Standard: Fire investigators in the burnt out window of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireFire investigators in the burnt out window of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, where a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“I got dressed, came outside and there was smoke billowing out from the back window,” he said.

He added a satellite dish on the house appeared to have melted, and said: “The heat - it doesn’t bear thinking about. It’s awful.

Wisbech Standard: People lay flowers at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WirePeople lay flowers at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“We hoped everyone had got out.

“They’re fairly new houses and they’re all fitted with fire alarms and things.

Wisbech Standard: The scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireThe scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

“It’s just awful.”

A GoFundMe page set up by a neighbour with a target of raising £1,000 for the family has reached more than £9,000.

Wisbech Standard: Neighbours bring flowers to the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireNeighbours bring flowers to the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

Wisbech Standard: Emergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireEmergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire

Wisbech Standard: Emergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA WireEmergency services at the scene of a house fire on Buttercup Avenue, Eynesbury, Cambridgeshire, in which a three-year-old boy and a seven-year-old girl died. A 35-year-old woman and a 46-year-old were also injured in the fire at the three-storey house, which police believe broke out around 7am Thursday morning. PA Photo. Picture date: Friday December 11, 2020. See PA story POLICE Eynesbury. Photo credit should read: Joe Giddens/PA Wire