Crews are expected to keep working Friday morning to get rid of all remnants of the Surry Hills blaze before investigations into how the fire started can begin.
There are also fears of further potential wall collapses.
Fire and Rescue NSW Superintendent Adam Dewberry said this morning the blaze was finally “pretty much out” with the last of the hotspots quenched by 2am.
But there remained a “very good chance” further walls could collapse.
“We are talking about tonnes and tonnes of bricks that could come down and become projectiles,” Dewberry told Today.
“That is why we have such a tight exclusion zone, not allowing anyone in, including firefighters, until we get the engineers in.”
Diversions are in place along Elizabeth, Randle, and Chalmers streets in the CBD.
Dewberry said the priority was getting people back into their homes and offices, but he warned there was a lot of work to be done.
Fire and Rescue NSW Commissioner Jeremy Fewtrell told media on Thursday evening it could take “several hours” to put out the fire completely.
“It will be a substantial and very prolonged duration of firefighting, to extinguish the fire completely,” he said.
Hundreds of people were evacuated from the area as the fire burned through several levels on Randle Street near Central Station just after 4pm on Thursday.
Authorities said it was “incredibly lucky” no firefighters were killed, though one suffered a minor arm burn.
More than 100 firefighters were called to the scene from multiple stations across Sydney, needing hours to contain the blaze with a combination of aerial and ground attacks.
Images even emerged of firefighters carrying dogs to safety away from the flames.
Fewtrell said there were “collapse zones” in place to protect firefighters as they kept working.
“We have some engineers attending the scene and they’ll help guide our decisions around safety considerations particularly around the risk of collapse,” he said.
Once the fire is finally extinguished, investigators from both FRNSW and NSW Police will enter the scene to determine the cause of the blaze.
Both organisations said it was too soon to speculate.
“Our fire investigators along with police forensics will start to make those assessments but that will be sometime downstream,” Fewtrell said.
Images reveal destruction in Sydney blaze
John Duncan from NSW Police said the matter was still under investigation.
“We will work with their investigators to work out what actually occurred. It’s way too early [to say what sparked the blaze],” he said.
Fewtrell asked anyone with information or video to come forward.
