As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIRST CLASS LAVATORY SMOKE ALARM WENT OFF DURING DESCENT, NO SIGN OF SMOKE OR HEAT. AN EMER WAS DECLARED & THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. INSPECTED FWD LAVATORY WASTE RECEPTACLE & FIRE EXTINGUISHING SYS. NO EVIDENCE OF SMOKE, FIRE OR OVERHEATING. REPLACED SMOKE DETECTOR WITH DETECTOR FROM AFT LAVATORY IAW MM 26-14-01. PLACARDED THE LT AFT LAVATORY SMOKE DETECTION SYS, MEL 26-15A. REPLACED THE AFT LAVATORY SMOKE DETECTOR IAW AMM 26-14-01. OPERATIONALLY CHECKED GOOD. THE ACFT WAS NOT GNDED.