As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RT ENGINE HAD A FIRE WARNING INDICATION AFTER TAKEOFF FROM LAX. THE AIRCRAFT WAS RETURNED TO LAX WHERE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND NO EVIDENCE OF FIRE. THE HP2 DUCT WAS FOUND LEAKING. THE HP2 DUCT WAS REMOVED AND REPLACED AND LEAK CHECKS WERE GOOD. A TEST FLIGHT WAS CONDUCTED AND THE RT ENGINE PERFORMED NORMALLY.