It's pretty obvious that the tail separated prior to the engines and/or wings. That doesn't mean engine debris didn't cause the tail to separate but the video looks like the tail is completely intact with little or no damage. In fact, the latest video looks like there are two "tabs" on the bottom of the tail just like those tabs on model airplanes your glue together. IOW, that tail looks like it was removed in a very neat almost controlled manner.
BTW, the nets are now reporting that reports of a wing separtion were incorrect and that the aircraft segments they thought were a wing were the tail segment.
but will somebody please explain how an entire vertical stabilizer comes off the jet intact before impact ???
I hope this doesn't go the way of Flight 800...