EXCLUSIVELalor Park tragedy: Dean Heasman's family breaks their silence after he was accused of killing his three kids in western Sydney house fire

EXCLUSIVE

A dying western Sydney grandmother has spoken of her shock at finding out her grandson is accused of killing his three children in a horrific house fire.

Dean Heasman, 28, allegedly barricaded his partner Stacey Gammage, 29, and their seven kids inside their housing commission home in Lalor Park, in Sydney's west, before setting it ablaze at about 1am on Sunday.

Two boys, aged three and six, were taken to Westmead Hospital in a critical condition but died from their injuries.

Once firefighters extinguished the flames, they also found the body of a 10-month-old girl. Her body was removed from the property during forensic investigations on Sunday afternoon.

Family matriarch Neryle Heasman, 82, told Daily Mail Australia she knew her grandson Dean as 'a nice child' but said she had been estranged from him in recent years.

'I didn't have a lot to do with him since his father, my son also named Dean, passed away,' she said.

'On the odd occasion I saw him, I remember him being a nice child.'

Dying grandmother Neryle Heasman has spoken of her shock at finding out her grandson is accused of killing his three children in a horrific house fire.

Dying grandmother Neryle Heasman has spoken of her shock at finding out her grandson is accused of killing his three children in a horrific house fire.

Dean Heasman, 28, and Stacey Gammage, 29, are pictured together. Three of their seven died in the blaze

Dean Heasman, 28, and Stacey Gammage, 29, are pictured together. Three of their seven died in the blaze

Mrs Heasman, who is receiving home palliative care for terminal lung cancer and has six months to live, said she had not met her great-grandchildren.

'I have kept up with his family through photos on Facebook,' she said.

But she was stunned to discover he was at the centre of the police investigation into the deadly fire. 

'Are you sure we're talking about the same Dean?' she asked Daily Mail Australia, and added: 'He is albino.'

Four other children, including a nine-year-old girl and three boys aged 11, seven, who were trapped inside the home, were treated at the scene and taken to Westmead Hospital in stable condition in the early hours of Sunday morning.

Their mother Stacey Gammage, 29, was treated for smoke inhalation while her de-facto partner Dean Heasman, 28, was arrested and taken to hospital under police guard.

Heasman allegedly threw a pillow on fire at his partner, which was partly responsible for igniting the blaze, reported the Daily Telegraph.

Investigators are also probing whether Heasman allegedly used an accelerant after a second explosion engulfed the home in flames moments after he threw the fully alight pillow at his partner.

 The father-of-seven is understood to have  no significant criminal history, but in 2017 did have a run in with the Australian Tax Office.

Then just 21, he pleaded guilty to making a false statement and was convicted, but avoided jail and instead was put on an 18-month good behaviour bond by the NSW Local Court - and was also ordered to pay back $2,809 to the ATO.

On Monday friends and members of the community arrived at the scene many leaving floral tributes, stuffed toys and candles.

Western Sydney grandmother Neryle Heasman, 82, is in home palliative care for lung cancer

Western Sydney grandmother Neryle Heasman, 82, is in home palliative care for lung cancer

Neighbours and family friends left floral tributes for the three kids who died on Sunday

Neighbours and family friends left floral tributes for the three kids who died on Sunday

The housing commission property in Lalor Park was quickly engulfed in flames in the early hours of Sunday morning

The housing commission property in Lalor Park was quickly engulfed in flames in the early hours of Sunday morning

Among evidence removed from the house were two water bottles containing a tea-like liquid

Among evidence removed from the house were two water bottles containing a tea-like liquid 

On Sunday detectives swarmed the home looking for clues on how the blaze began, and whether a fire accelerant had been used.

Among the evidence removed from the house were two water bottles with a tea-coloured liquid inside.

Police allege Heasman held the front door shut when emergency services arrived and shouted, 'Let me die here' as the children screamed for help inside.

Heasman is reported to have suffered burns to his skin and throat and the affects of smoke inhalation during the tragedy and is now in an induced coma as detectives wait to interview him.

Neighbours told Daily Mail Australia that all three front rooms of the home were quickly engulfed with flames, before power lines began to spark and snapped off the house.

Local resident Jarrod Hawkins, whose daughter was friends with one of the surviving children, was hailed a hero after rushing to the burning home and saving a nine-year-old girl and her three brothers, aged four, seven and 11.

The eldest boy told his rescuers: 'Dad tried to kill me.'

Once Mr Hawkins left the burning home with four children, they were placed on the other side of the road before another neighbour Damien Dubois decided to move them away from the scene.

Emergency services, including at least 20 firefighters and six fire trucks, rushed to Freeman Street following reports a home was ablaze

Emergency services, including at least 20 firefighters and six fire trucks, rushed to Freeman Street following reports a home was ablaze

Dean Heasman, 28, was arrested at the scene and taken to hospital under police guard

Dean Heasman, 28, was arrested at the scene and taken to hospital under police guard

'I had the four kids and they were cold so we picked them up and took them into the back room of my place,' Mr Dubois told Daily Mail Australia.

'I was trying to console them. The two younger kids weren't saying anything so I picked them up and took them out of the way of all this trauma.

'They didn't need to watch it all.'

Mr Dubois recalled Heasman taking some of the children on quad bike rides around the local neighbourhood just a few weeks ago.