Haven't they say many times already that their buildings will survive?
In my personal experience, although short for now, telling them that the matter is private and personal could lead to more inquiries in some cases but is not a bad idea. Sometimes they will remind you that you can have privacy with them as if you were speaking to God directly. Whatever you decide to say, playing a game of confusion would always work best. Keep them guessing. The more theories they have the better. If they insist to meet with you, see if you can find a way to meet with different elders at different times. Make sure you don't re use your excuses. Tell different people different things, especially if you know they will be discussing them with one another.
This game of confusion has managed to keep the UFO theories alive and well without ever reaching anything conclusive. Could well work here.