Noone got hurt
Those tunnels are, respectively - new railway link tunnel in Sydnet (12km tunnel), and a new under-city bypass tunnel in sydney. The shots you see are in a vent shaft / rocket chamber, etc etc.
And yeah, you'd expect security, but they don't seem to give a fuck. Didn't see a single one
There were a few concrete trucks etc rolling thru the train tunnels the first night, but luckily, they were keeping their eyes on the wheel.
the first few snaps are from an abandoned TV station. The gravestone thing is a mate sitting in front of a prop in a massive rehersal room