Two teenagers are assisting police with their inquiries after a major blaze destroyed a seven-storey heritage-listed building in Sydney's inner city.
The more-than-a-century-old former Henderson Hat factory on Randle Street, Surry Hills, was gutted by fire just after 4pm on Thursday.
At a press conference on Friday, NSW Police Acting Assistant Commissioner Paul Dunstan said a group of young people were seen running from the scene.
He said two 13-year-olds had handed themselves in at two separate police stations last night, and are assisting with their investigations.
Police are aware of three or four other young people who were present, and are urging them to come forward with their parents.
"The two people we have spoken to are 13 years of age, we believe the other people are of a similar age."
Some of residents in neighbouring buildings forced to evacuate on Thursday, have been allowed to briefly return to their homes.
They have been told they can gather essential items but cannot stay as there's no power, and there are safety concerns.
Fire and Rescue NSW (FRNSW) Superintendent Adam Dewberry says the building behind the fire is too dangerous for people to visit even briefly.
"The residents at the rear in Chalmers Street, who have been evacuated, they are not allowed to go back in at the moment," he said.
"Because of the significant concern we have with the rear wall of the building and the potential for that to collapse."
Specialist equipment, including a laser monitor, is on site to detect whether there's any new movement in the walls damaged by the fire, according to FRNSW.
Defining fire for officers
FRNSW Acting Commissioner Jeremy Fewtrell described the blaze as a "once-in-a-decade type of fire".
He said for all the firefighters who attended it was a "really defining point" in their careers".
"The one thing I can guarantee at the end of their careers, this is one of the highlights they will reflect upon."
Fire crews worked through the night to mop up "the extremely intense fire" while some of the walls posed a significant threat of falling down, FRNSW Superintendent Adam Dewberry said.
Pockets of smouldering fire remain but are under control.
"[It was] a rapidly escalating fire, very intense, an abandoned building, old timbers, dried out timbers, and in some reports, rotted out, which all contributed to the significant intensity and spread of this fire," he said.
Up to 15 people were believed to be sleeping rough inside the heritage-listed building the night before.
Some nearby residential buildings were initially under threat due to spot fires at the height of the blaze and have been affected by radiant heat damage.
"Windows have started falling out of buildings across the road, and that's a danger in itself," Superintendent Dewberry said.
"We’ve still got a problem with two walls that are in precarious positions, and that could come down without notice, bringing tonnes and tonnes of bricks down and causing projectiles."
All residents were evacuated safely and forced to find alternative accommodation while fire crews carried out risk assessments on the structural integrity of neighbouring apartment blocks.
Firefighters were also able to retrieve a wedding dress for a bride-to-be who lived in one of the nearby buildings.
Acting Commissioner Fewtrell said it was too early to tell what caused the fire, with investigators waiting for the scene to be made safe to enter.
"Our fire investigators along with police forensics will start to make those assessments but that will be some time," he said.
"We have some engineers attending the scene and they will help guide our decisions around safety."
Sydney artist Jozef Szekeres was among the dozens of residents who spent Thursday night away from home.
Mr Szekeres owns an apartment on Randle Street, very close to the historic building.
When he made it back to his street late on Thursday night, he was met with a large exclusion zone, with police officers stopping residents from returning.
"They said they need to check the structure," he said.
"It was two buildings across, where the fire started … but it did come into the one in between, so we have a common wall that the fire was against, so that's very concerning.
"I'm just hopeful that everyone was out of there and safe."
Acting Commissioner Fewtrell said it remained unclear what the vacant building and adjacent structures were being used for.
"At this stage, the buildings were vacant or unoccupied, whether they were under construction or about to have demolition or work done, but certainly there have been no reports in any of the information we have been able to source."
The building was set to be turned into a 123-room hotel, according to a development application lodged with the City of Sydney by developer Hanave Pty Ltd in 2019.
The plans stated the adjacent buildings at 7-9 and 15 Randle Street would be knocked down, while 11-13 Randle Street would be retained.
A nine-storey building was set to be constructed across the sites at an estimated cost of $40 million, according to the development application.
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