Read more: 'Extremely traumatic scene': all the answers from emergency crews

A GRANDMOTHER is dead, a mother is fighting for life tonight and one of her children has died after a fierce fire ripped a Tamworth home this morning.

The deadly blaze in Bylong Road claimed the life of the grandmother in the front bedroom as well as a five-year-old boy in a back room - an extremely traumatic scene for fire crews and police who tried to save them.

A seven-year-old boy is recovering in Tamworth hospital from minor injuries and smoke inhalation, after he miraculously managed to make it out of the home, which was engulfed in flames just before dawn.

His mother - a 27-year-old Tamworth woman - suffered "severe and significant burns" to much of her body and has been flown to a specialist burns unit at a Sydney hospital.

Her condition continued to deteriorate throughout the day and she was listed in a critical condition tonight.

A 60-year-old man who lived at the home is the prime suspect in the suspicious fire. He handed himself in to Tamworth police shortly after the blaze erupted and spent much of today being questioned by detectives.

"That male person has received injuries; he has now also been transported to Tamworth base hospital under police guard for treatment of those injuries," Oxley Acting Superintendent Kylie Endemi said.

Police won't confirm the relationship between the man and the victims, but said he "is known to police" and has been "assisting with inquiries".

"We can confirm that he was known to the victims and that was his primary place of abode," Superintendent Endemi said.

"At this time, we are certainly treating this fire as suspicious.

"Strike Force Glendare investigators are certainly working extremely hard to find out exactly what has transpired at this location."

The strike force - which is made up of Oxley and New England detectives and is backed by the state's arson squad - spent the day combing the fire scene.

They also spoke with emergency services as to what they'd been confronted with, and have also questioned the prime suspect. No charges have been laid.

While the man is under police guard, and the mother is still critical, detectives are trying to piece together the moments before the fire - which is believed to have been deliberately lit - erupted.

Neighbours rang triple zero after they saw flames leaping from the house about 5.30am.

Superintendent Endemi has praised the first fire crews and police first on scene, along with neighbours, who tried everything to save the young boy and his grandmother.

She said the scene was "extremely tragic and extremely traumatic".

"All officers are being supported through this difficult time, many of whom have children of their own," she said.

"I want to make a special mention of the heroic actions performed by our first responders, who were trying to assist the victims that were still inside this home.

"Unfortunately, the ferocity of the fire prevented them from gaining access and assisting the victims at the time."

Superintendent Endemi said "their actions and the assistance" from neighbours was "nothing short of commendable".

"My information was there was a number of community members who tried to assist these victims and emergency personnel that were our first responders," she said.

"This is an extremely tragic set of circumstances for everybody involved ... but certainly for my officers, and I'm aware that my emergency service colleagues are also suffering at this time.

"Any situation of this nature is extremely difficult, especially one that involves children.

"As I said, many of our staff have young children and that makes it certainly difficult to deal with, but we are assisting them to deal with it.

"We have plenty of support mechanisms wrapped around them at this time and we will help them through."

Ambulance NSW Inspector Paul McKay said his paramedics did everything they could for the patients. He said the mother and son were outside the home by the time paramedics arrived on scene.

"I think this is something that is a bit of a shock to everybody, especially emergency services and certainly confronting for the community of Tamworth," he said.

"It's something that we don't normally have to manage in this community."

Fire and Rescue NSW Superintendent Tom Cooper said city crews were on scene within eight minutes of the emergency call, and the West Tamworth crew was two minutes behind.

"They gave themselves the best chance to rescue the people that were trapped, but they unfortunately were too late by the time they got there," he said.

Firefighters did not have access to town water at the weatherboard property, but a full tank and water-carting meant crews could still attack the fierce fire.

"There was a static tank in the backyard [that was used]. The nearest reticulated water supply was two blocks away," Superintendent Cooper said.

"They were backwards and forwards with the tankers to refill one, but at no stage did we have interruption to water supply due to the quick thinking of two firefighters from West Tamworth, who latched into a static tank and provided constant supply while the crews went and filled up their tankers at the hydrant.

"It was only from the grace of God that it had rained recently and that tank had topped up by the recent rain."

Superintendent Cooper said his firefighters were being counselled after the "confronting situation", especially because "children are involved".

He said two particular firefighters were being closely monitored after what they had to endure in the firefight, and chaplains from St Nicholas and Ambulance NSW had been helping.

Support the local news that keeps you informed - subscribe today