Police and fire investigators will launch an inquiry into the circumstances of Unanderra house fire, where a "mountain of household items" hoarded inside the building fuelled a massive blaze.
The fire, which started around 10am in a two-storey brick home on Beatus Street, prompted a large scale response after plumes of black smoke were seen billowing into the air.
With access to the house made difficult due to a large amount of hoarded household items inside and high winds fanning flames, Illawarra duty commander inspector Chad Wallace praised the rapid response from fire crews.
"On route, the first three units could see a big plume of smoke and the number of calls to Triple 0 lit up, so we escalated that to include 10 fire trucks and an incident commander, and we also deployed our specialist cherry picker and a heavy rescue appliance," he said.
"Firefighters were on scene within a matter of minutes and quickly deployed resources.
"There was a lot of flame to start with, and that was because of the significant fuel load in the house."
He said the man living in the house met firefighters out the front of the burning building and was able to assist them to gain access, which was made difficult by the hoarded items inside.
"He gave us critical information, including about gas cylinders and electricity and the like, and he was also able to confirm for us that there was no other further persons in the house, which let us concentrate the efforts on putting the fire out," he said.
Firefighters threw various items - including the hot water system, whitegoods and various household detritus - out of the house to give them better access.
Dozens of neighbours watched as flames burst out of the house, shattering the windows, but were moved back behind an exclusion zone when plumes of black smoke filled the air.
Inspector Wallace said the rapid response kept the fire from encroaching on any neighbouring homes, despite strong winds
"It was a phenomenal effort by firefighters to arrive so quickly and under such hazardous circumstances work to contain the fire," he said.
Just before midday, as crews continued to put out the flames, Inspector Wallace said the home had about 70 per cent damage from the fire, as well as water damage, which meant they had been unable to pinpoint where or how the fire may have started.
"The incident is about to move into an investigation phase, where firefighters and investigators, and NSW Police will deploy all resources to work out how and why the fire started."
A spokeswoman from NSW Police confirmed detectives were investigating the circumstances surrounding the fire.