As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CERAMIC PORTION OF THE SPARK PLUG BROKE COMPLETELY AROUND AND ALLOWED THE SPARK PLUG WIRE TO FALL OFF WITH THE PIECE OF CERAMIC INSIDE THE WIRE AND CAP. ENGINE WOULD NOT MAINTAIN POWER ON 1 CYLINDER CAUSING FORCED LANDING AND DAMAGE TO AIRCRAFT.