It’s an unsafe worksite.
This is how I’d handle it:
Call SafeWork NSW ph. 13 10 50 and inform them of the immediate danger this unsafe worksite poses to the public, especially children.
Request a site visit by a Workplace safety inspector.
Complete the call with an email to the department officer with explanatory photos.
Copy in the Owners Corporation secretary and ask them to notify their insurer under their duty of continuous disclosure.