"You are probably right. Since my original post I have talked to a
local tile
store and that is their thoughts from my description, I have tapped the

tiles at the suggestion of another response and and found quite a few
hollow
sounding tiles through out app. 600 sq. ft. so i'm prepared for the
worse
and going to call a contractor in. "

Assuming that's the only issue, it doesn't explain how after 7 years,
so many suddenly come loose in one or two days. This typically would
happen with them slowly cracking or coming loose over a longer period.
I think some kind of earth/foundation movement occurred and the
installation could be a contributing factor.