As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: SMOKE LAVATORY WARNING ILLUMINATED AND ALARM IN CABIN SOUNDED AT LAVATORY 3R. NO SMOKE WAS CONFIRMED BUT PASSENGER IN LAVATORY HAD AN E-CIGARETTE. WARNING LASTED ABOUT ONE MINUTE. PERFORMED OPERATIONS TEST OF SMOKE DETECTOR AT LAVATORY 3RL AND 3RC PER AMM 26-13-00. NO FAULTS FOUND.