I have had a closer look and it may in fact be 2 floors, I have used the top picture you posted Locutusofbored and I have added highlights to show the floors (amateurish using paint I know).
Nope. The corridors are not the same height as the windows. In fact, if you look through the windows, you can see only one of the three rows of "rectangle" patterns on the walls. Your red arrow is also pointing at what I assume you think is a floor, but it isn't.
I don't mind if you agree or not WarpfactorZ, it looks like whats left of a floor to me and it is in line with the idea of 4 floors in the saucer rim as many here have shown.
The area exposed by the damage is far too large (height) an area to be just one floor, whether you like it or not.