Thanks to everyone for following along on a chaotic night in Sydney.

Here's a round up of some key developments:

• A fire broke out in a heritage-listed building in Surry Hills about 4pm
• 120 firefighters and 30 trucks attended the three-alarm blaze
• Only one firefighter received minor injuries
• Parts of the building collapsed onto Randle Street below as fire tore through the property
• The blaze was contained just before 6pm
• NSW Police and Fire and Rescue NSW will investigate the cause of the fire
• The site is a former hat factory for the RC Henderson company

We will be updating our stories on the fire as the night goes on.

Safe night all!

Hopefully this answers your question.

And here is some footage taken by people who witnessed the events unfold today.

The Randle Street property is a heritage-listed site, which was formerly the RC Henderson hat factory.

 It was set to be turned into a hotel, according to a development application lodged with the City of Sydney by developer Hanave.

A member of the Henderson family, which built the factory in 1912, rang ABC Radio to share a bit more about its history.  

James Henderson’s aunt Elizabeth, the daughter of company founder Rolla Crosley Henderson, used to work there as a saleswoman. 

He spoke to her this afternoon. 

“She’s totally beside herself, she’s in her mid-90s.

“[The company] started in 1911 and they built the building in 1912 and it’s been there ever since up until now which is quite shocking.

“The story goes that it was the brother-in-law of RC Henderson that designed the building so it was all in the family.

“I used to always visit that location just to look at the building cause you could look up and you could still see the sign-writing ‘RC Henderson’ at the top of the building so it gave you the warm fuzzies as a Henderson but now it’s gone.”

Just responding to your question, Kath.

Authorities say Central Station is running as normal.

But please keep this in mind.

Fire and Rescue NSW Acting Commissioner Jeremy Fewtrell said people living or working around the scene should keep their windows and doors closed.

"We ask people to try to stay out of the smoke and avoid it"

The cause of the fire is yet to be determined.

He said the heritage building with wooden fittings erupted quickly.

"It was an incredibly intense fire."

There's a press conference underway now.

The fire has been "effectively contained".

One firefighter received a "minor injury" in the form of a burn to his arm.

"The information we have at this stage is the buildings were vacant."

People have told reporters about how the ground shook when parts of the burning building started to collapse.

“A huge flume of smoke came up and that whole wall just caved in,” witness Grace Turner said.

“It was the loudest noise. The ground shook.”

Korin Ellis said he came up from central station in time to see the building collapse.

“All you could feel when you were standing there was heat on your face from the flames. You could hear tyres exploding,” he said.

“I saw a couple of people running and crying."

And here's testimony from one our readers:

Ethan

5:25:44 PM

I was training for soccer at moore park west when the fire started. We saw the smoke rise up and helicopters and a police car drove across the field. We walked to take the tram to see them cancelled so we continued to central to see the fire. There was ash falling from the sky and the fire was bright red.

There were more than 100 firefighters and 20 trucks battling to  contain the fire.

Fire and Rescue NSW has just shared this footage:

Here was what Superintendent Adam Dewberry told us earlier:

The fire took hold quickly in a seven-storey building on Randle Street in Surry Hills shortly after four this afternoon.

The fire has destroyed the building with parts of the walls falling onto nearby cars adjacent to central railway.

Crews had to put out spot fires on nearby home unit balconies.

Police and ambulance crews also quickly responded to the escalating blaze.

These shots were snapped by AAP photographer Dean Lewins earlier this afternoon.

He captured the moment walls began to crash down onto the street.

Thanks to everyone for your comments and questions.

To answer a few of you, thankfully there are no reports of injuries so far.

A few of you have also been asking about this:

Will

5:17:34 PM

do we have any idea as to what floor this started on or what started the blaze?

That remains unclear at the moment but it will be part of the investigation once the site is deemed safe.