A senior investigator says a blaze at a Stockton unit that claimed the life of 55-year-old Graham Cameron early on Monday morning was "wind-driven" and intense - likely to have been up around 1000 degrees.
Police and fire investigators were expected to remain at the scene at Fullerton Street well into Monday, as they try to figure out how the inferno began just after 5am.
Mr Cameron, who lived in the unit, died in the fire. Emergency crews were able to rescue a woman from a neighbouring flat.
She was assessed by paramedics and did not require immediate hospital treatment.
Fire and Rescue NSW investigation manager Superintendent Greg Symonds said the unit - on one end of a block of five single-level homes - was well alight and "almost totally destroyed" when firefighters arrived at the scene.
Superintendent Symonds told the Newcastle Herald that it was too early to tell what started the blaze.
"It was a wind-driven fire with very strong wind gusts," he said.
"The fire had vented so it wasn't oxygen-controlled - it would have been a very intense fire, probably up around 1000 degrees.
"There's a lot of fire damage inside. We'll need to dig down to determine the cause, if we are able to do that."
Three of the units were severely damaged by the fire.
Forensic Services police are also investigating the scene.
Newcastle City police commander Detective Superintendent Wayne Humphrey said the scene would take "a long time to process".
The tragedy comes after a family made a lucky escape, uninjured, when a two storey home went up in flames on Sandgate Road at Shortland in the early hours of Sunday morning.
"With these really cold temperatures - we've still got a lot of winter to go - make sure you've got working smoke alarms, make sure you keep heaters at least a metre away from flammable substances and don't overload powerboards," Superintendent Symonds said.
Officers from Newcastle City Police District have established a crime scene and started an investigation into the circumstances surrounding the incident.
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