As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WINDING UP FOR T/O HEARD AUDIBLE ENGINE SURGE/STALL PASSENGERS OBSERVED FLAMES COMING FROM LEFT ENGINE. A/C RETURNED TO GATE. MTC INSPECTED TAIL PIPE FOUND BB SIZED DEBRIS. WILL NEED ENGINE CHANGE. REPLACED NR 1 ENG PER ROUTINE CARD DECK TRANS 6T103.