As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FRONT BEARING ON THE ALTERNATOR HOUSING FAILED CAUSING THE HOUSING THERE TO BE DAMAGED, THE BELT TENSIONING STRAP TO THE ENGINE CASE TO CRACK AND THE ROTOR TO FALL LOOSE ENOUGH INSIDE THE HOUSING TO DESTROY THE ELECTRICAL GENERATING CAPABILITIES OF THE ALTERNATOR. THE CAUSE OF FAILURE WAS NOT CLEAR, ENGINE/PROPELLER VIBRATION WAS DETERMINED TO NOT BE A SIGNIFICANT FACTOR.