Workers flee collapsing Sydney office building

An office block has collapsed on Sydney's North Shore, sparking a hurried evacuation.

Workers in the building had noticed the new cracks which had emerged around the windows.

But it quickly became clear they weren't just cosmetic.

"Windows started giving way, so it was pretty clear there was a big problem," building manager Penny Flannagan told 9News.

Ms Flannagan, who has managed the building for 34 years, raced through all four storeys to get everybody out.

"I was in the middle of a Zoom meeting with some directors and the manager comes in and screams, 'get out, get out, get out, get out'," worker Elliot Geleris said.

The building was thankfully emptier than usual due to the long weekend, and all 10 occupants escaped just in time.

There are fears that the building remains a danger, with NSW Fire and Rescue creating an exclusion zone.

They are worried more of the office block could collapse.