The only thing I can think of is if the oil was severely over heated
   or no
   oil at all and the silver/aluminum bearing linings melted and
   soldered the
   e-shaft to the block. It has happened before. Finn Lassen started up
   his engine
   with no oil cooler plumbing nor oil pressure, stuck in WOT and the
   engine buzzed
   up to about 10,000 to 12,000 RPM and seized or stopped. The oil
   cooler is first
   in line after the pump.  He chiseled it apart, put new bearing shells
   in and flew it for the next five years until he crashed in the woods
   at Tracy house trying to land at night. (No runway lights or any
   other lights
   for that matter.) He was not hurt fortunately. Finn leads a charmed
   life.

   This is sounding more and more like a tension bolt failure. I can't
   explain the
   simultaneous loss of the alternator however. Also Dave, you said the
   prop was
   still wind milling so the engine did not seize. This is a big
   mystery and I
   can't wait to examine the evidence.


Correct, afterward the prop turned by hand very easily.  It was still
connected to the engine but there was zero compression.