As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE FIRE LOOP B LIGHT ILLUMINATED AFTER DEPARTURE. ALL OTHER INDICATIONS NORMAL. FOLLOWED QRH NOTIFIED ATL MTC OPS NORMAL REMAINDER OF FLIGHT. INSPECTED LT LOWER PYLON BURN THRU DETECTOR AND FOUND LOOPS RUBBING AGAINST FLUID PIPE. DETECTOR WORN THROUGH HALF WAY. R&R LT ENG PYLON BURN THRU LOWER DETECTOR IAW AMM 26-10. OPS TESTED GOOD.