As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK - INFLIGHT LGA-DFW. ON TAKEOFF AFT CARGO COMPARTMENT OPEN INDICATION ILLUMINATED. EMERGENCY DECLARED DIVERTED JFK LANDED WITHOUT INCIDENT. AFTER LANDING EXAMINED AFT CARGO DOOR FOR DEFECTS AND SECURITY. DOOR WAS FOUND TO BE PROPERLY CLOSED AND LOCKED. REPLACED PROXIMITY SENSOR. SYSTEM GROUND CHECKED NORMAL OPERATION.