If I were you ^^^ I would not mention this online, frankly. It could get you in legal trouble. I would strongly advise editing your comments to place everything in the hypothetical subjunctive!
The story on why they won't let people in is that there is a fair amount of asbestos in there. It is very dusty and such in there and the security gentleman I spoke with said they never de-asbestified it, and he would only go in with a respirator. He looked me in the eye and very sincerely begged me not to risk my health. I said thanks and what about a waiver, he said forget it, they'd have too many people signing a waiver and then what about all the lung cancer.... So I didn't press the issue.
Just do not risk your health for interior shots, trust me it's not worth it.