As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, THE NR 1 ENGINE FIRE INDICATION ILLUMINATED. CHECKLIST PROCEDURE FOLLOWED AND ENGINE WAS SHUT DOWN AND FIRE BOTTLE BLOWN. INDICATION CASED. SAFE LANDING MADE AT DEPARTURE AIRPORT. NO VISUAL INDICATION OF ENGINE FIRE. INVESTIGATION REVEALED THE ENGINE FIRE LOOP HAD BECOME DISPLACED AND WAS CONTACTING A BLEED AIR PIPE. FIRE LOOP REPOSITIONED. FIRE BOTTLE REPLACED AND GROUND RUNS REVEALED NO FURTHER DISCREPANCIES.