This sounds like a simple mechanical clutch failure to me. Personally, I have never heard of this happening to one of our cars in the ten years I've been on this forum, but it stands to reason that the clutch is simply disengaged - for some reason, due to some failure.

I think the only option you have is to tear into it and see what you have. Look at the good side: This is a mechanical issue, so you will have no electrical mystery to figure out, like we do MOST of the time with these cars.

This is simply mechanical - and I do not see how it can be ANYTHING but a clutch failure.