As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT 5004, AFTER ARRIVAL AT GATE WITH JETWAY ATTACHED. EXTERNAL CORD HOOKED UP TO PANEL, AND A FIRE STARTED AT CORD/PANEL AREA. DEPLANING WAS IN PROCESS; THE CABIN BEGAN TO FILL WITH SMOKE TO THE POINT THAT EVACUATION VIA THE OVERWING SLIDES AND THE L2 AND R2 DOOR WERE NECESSARY. FIRE DEPARTMENT EXTINGUISHED FIRE. CORRECTIVE ACTION: NTSB IS INVESTIGATING, CURRENTLY NO AIRCRAFT SYSTEMS WERE FOUND AT FAULT. FAULT FOUND WITH THE GROUND POWER CABLE. (LP 0333541)