There is another staircase to a fourth floor.

Did I climb it? Sure I did.

But going into abandoned buildings is potentially very dangerous. There are serious risks of falling through floors, cutting yourself up on broken glass, having pieces of the roof fall on your head, stabbing yourself with rusty metal, etc. No one is keeping an eye on the state of the buildings and the things that are inside them, so you're entirely at your own risk. This particular building is very damaged, and when I looked at the roofs from the lower floors I wasn't sure if I wanted to go up there at all. But I was careful to stay close to the walls and tread very lightly.
So, do not attempt this. Let crazy (and lightweight) daredevils like myself bring you these views on photographs, and enjoy them safely at home.