Neighbours were evacuated as hot and windy conditions fanned flames that tore through a Tarrawanna home on Wednesday.
The fire is being treated as suspicious, with Fire and Rescue NSW investigators and forensic police called in to assess the badly-damaged structure on Kendall Street.
The area remained a crime scene, cordoned off by police tape, on Thursday morning.
A sniffer dog was brought in to help search for clues as to what sparked the inferno, while police detectives canvassed the area.
FRNSW Corrimal station commander Paul Dorin told the Mercury the fire was believed to have started in a room at the rear of the house.
“It [the cause] is undetermined at this stage, but does look suspicious,” Mr Dorin said.
Fire crews from Balgownie and Corrimal were called to the fibro and tile home, opposite Tarrawanna Public School, about 6pm on Wednesday.
The house was well alight when crews arrived.
Firefighters managed to quickly put it out, despite battling temperatures of about 37 degrees and winds gusting in excess of 45km/h.
“It was a hot afternoon and the wind had just picked up, so we were a little bit concerned about the exposure of a neighbouring house on the eastern side,” Mr Dorin said.
“We evacuated the neighbours and we got hoses onto it pretty quickly.”
The fire was upgraded to a “second alarm” response, which saw additional crews from Wollongong and Warrawong brought in. FRNSW’s Illawarra duty commander also responded.
The house was extensively damaged. No one was home at the time and no one was injured.
Mr Dorin said the Tarrawanna fire call came on a “busy day of fighting fires”.
Earlier on Wednesday, FRNSW crews and their NSW Rural Fire Service counterparts responded to fires in the southern Illawarra, including one that closed the Northcliffe Drive on-ramp to the M1 Princes Motorway at Berkeley for a short time.
Severe fire danger is forecast for the Illawarra/Shoalhaven on Thursday and a total fire ban remains in place across the region.
Mr Dorin’s message to residents was “just to be vigilant”.
“Just take any warnings from emergency services if they’re involved in any fires in their location, just heed the warnings,” he said.