As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN SMOKE DETECTOR WARNING LIGHT ILLUMINATED INFLIGHT. MADE ATB BACK INTO BRADLEY, AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. OFF LOADED AIRCRAFT, INSPECTED ALL CONTAINERS AND CARGO PITS FOR SMOKE. FOUND NO EVIDENCE OF SMOKE OR FIRE. TESTED ALL CABIN SMOKE DETECTORS. OPS CHECKED NORMAL.