Pictured: The three young children killed in Hunter Valley house fire tragedy

The three children who died in a ferocious house fire in the NSW Hunter Valley have been identified as tragic new details emerge about the blaze which killed them.

Matylda and Scarlett, 5, along with their brother Blake, 11, all died after a fire ripped through their home at Brittliffe Close, Singleton about 3.30am on Wednesday morning, according to a GoFundMe page.

The two little girls were rushed to Singleton Hospital but died soon after. Blake was later found dead inside the home.

Their mum Kara and sister Bayley, 8, are being treated at John Hunter Hospital for smoke inhalation. Ms Atkins also has burns to her back and forehead, but both are in stable conditions.

Matylda and Scarlett Atkins (picture on the left and second from left) died alongside their brother Blake (on the far right) in a house fire at Singleton on Wednesday morning. Their sister Bayley (pictured second from the right) survived. Source: GoFundMe
The house fire which claimed the lives of three kids in Singleton on Wednesday morning. Source: Nine News

Fire and Rescue NSW Superintendent Joshua Turner told reporters the rescue operation to save the boy was “extremely difficult” after four people had been removed.

“Unfortunately, no further internal fire fighting operations could continue due to the intensity of the fire and the risk of the structure collapsing,” Supt Turner said.

“On further search and rescue, once it was safe to do so, a further fifth person was unfortunately found within that residence.”

It's not known what caused the fire yet. Source: Nine News

It is believed the children attended King Street Public School in Singleton.

After Yahoo News Australia contacted the school for comment a NSW Education Department spokesperson responded, saying the school had "expressed its deepest sympathy" to friends and family of the children.

"Counselling is being provided at the school for students and staff, and the school can assist parents in supporting their children," the spokesperson said in a statement.

"The support will remain available as necessary."

‘Heroic’ neighbours save woman and child

Supt Turner said on arrival four residents were found fighting the fire. They too had tried to rescue those inside by going through the front door but “the heat and the intensity” meant they had to leave.

They used a garden hose to fight the blaze.

Hunter Valley Police District Commander Superintendent Chad Gillies added the four residents did, however, manage to help get the mother and the eight-year-old out of the home.

Supt Gillies called their actions “heroic”.

The roof of the home. NSW Fire and Rescue said four residents tried to fight the fire and managed to save a 31-year-old woman and an eight-year-old boy inside. Source: ABC

What caused the fire?

It’s not know what caused the fire but a crime scene has been established.

Supt Turner said neighbours heard smoke detectors on arrival “and the sound of broken glass caused by the fire”.

He added the fire appeared to start at the front of the house before moving to the back. The two girls were in separate rooms and were removed via their windows.

“We've seen, particularly in this area over the last few weeks, that a large number of fires have been caused through heating alliances and so forth, and coming into winter, that is a major contributing factor to fires,” Supt Turner said.

“So obviously, knowing that there was a fire place in the vicinity, it will be a major point of investigation.”

Authorities said the fire started at the front of the home before spreading to the back. Source: ABC

‘Everybody knew them’

Supt Gillies said another part of the ongoing investigation will be working with Singleton’s grieving community.

“We're all in this together,” he said.

“These things tear at the heart of a local community like Singleton.

“Everyone knows someone here, so from our perspective, it will now be about certainly working through today and getting the necessary things done in terms of the crime scene and the ongoing investigation.”

Resident Rebel Maskey told the ABC all the children in the area play together.

“It's going to affect them all," she said.

"Everybody knew them."

Do you have a story tip? Email: newsroomau@yahoonews.com.

You can also follow us on Facebook, download the Yahoo News app from iTunes or Google Play and stay up to date with the latest news with Yahoo’s daily newsletter. Sign up here.