As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LIT - PHL TO DFW - AFT CARGO FIRE WARNING LIGHT ILLUMINATED. EMERGENCY DECLARED AND LANDED LIT WITHOUT INCIDENT. AIRCRAFT INSPECTED AND CONFIRMED NO FIRE. REPLACED CARGO COMPARTMENT SMOKE DETECTOR. SYSTEM GROUND CHECKED NORMAL OPERATION.