As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ICT INFLIGHT TUL-TUL (FCF). CREW REPORTED FIRE WARNING BELL WITH NO FIRE WARNING LIGHT INDICATION. FLIGHT DIVERTED ICT LANDED WITHOUT INCIDENT. RESET FIRE WARNING CIRCUIT BREAKERS AND ACCOMPLISHED FIRE WARNING TESTS. ALL TESTS NORMAL. REPLACED LEFT AFT LAVATORY SMOKE DETECTOR. SYSTEM GROUND CHECK NORMAL OPERATION.