As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ARRIVAL WITH EXTERNAL POWER CONNECTED, VISIBLE FLAMES WERE NOTICED COMING FROM THE EXTERNAL POWER PANEL. SMOKE ENTERED THE ACFT THROUGH DOOR L1. PASSENGERS WERE SAFELY EVACUATED THROUGH THE AFT BOARDING DOORS. THE TAILCONE AND ITS' SLIDE FAILED TO DEPLOY.