Two people have died after a house fire north-west of Sydney, which saw the roof of a two-storey house collapse.
Five people, a man and four children, were able to escape from the home on Lieutenant Bowen Road in Bowen Mountain, which is believed to have broken out at around 2am.
However, two people, believed to be children, were unaccounted for at the time.
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The blaze was so fierce that it caused the roof of the home to cave in, forcing firefighters to temporarily retreat and take defensive action.
NSW Rural Fire Service Commissioner Trent Curtin said it was a "very difficult" task for firefighters, with 12 trucks and around 50 people responding to the blaze, but said they had no choice but to initially take defensive action.
"Firefighters want to get in there with their hoselines and getting in and locating people who might be missing, but an early assessment of the building recognised that parts of the walls were looking to collapse, and parts of the structure had collapsed," he said.
"It would have been too dangerous to go inside the home while it was collapsing."
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It took around two hours for the blaze to be contained, with Curtin confirming firefighters were now able to gain access to some parts of the house.
"Some parts of the home are hot and smouldering, and many parts of the home have collapsed," he said.
After further search efforts this morning, police confirmed two bodies were found inside the home.
The bodies have not been formally identified, but a crime scene has now been established.
NSW Ambulance confirmed four people had been taken to Nepean Hospital for smoke inhalation and minor burns; these included a male teenager and two primary school aged boys.
Curtin praised the actions of responding crews to ensure the fierce fire didn't spread to other homes, and he said all firefighters would be offered support.
"[It's] very tough for our firefighters… all of those firefighters are impacted by the circumstances," he said.
Investigations have commenced into how the fire started.
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