As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING NR 2 ENGINE START DURING/AFTER PUSHBACK FROM GATE, TAILPIPE FIRE OCCURRED. FIRE SELF-EXTINGUSHED ON ENGINE START. NO COCKPIT WARNINGS WERE NOTED BY THE FLIGHT CREW. HOWEVER PASSENGERS PANICKED AND DEPARTED THE AIRCRAFT THRU EMERGENCY EXITS. ALL SLIDES PERFORMED AS DESIGNED. REPLACED EEC PER AMM DUE TO FAULT CODE.