As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD LAV SMOKE ALARM WENT OFF IN CRUISE. NO EVIDENCE OF FIRE OR SMOKE. ONLY ON FOR ABOUT 5-10 SECONDS. PAX MAY HAVE BEEN VAPING BUT NO EVIDENCE. REMOVED FROM SERVICE. NO EVIDENCE OF FIRE/SMOKE IN FWD LAV. GVI OF FWD LAV SMOKE DETECTOR, NO DEFECTS. OPS TEST OF FWD LAV SMOKE DETECTOR IS GOOD, REF AMM 26-14-01-700-801A. NO DEFECTS NOTED AT THIS TIME. RETURNED TO SERVICE.