As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - FLIGHT 2120 - THE LAV SMOKE DETECTOR SOUNDED FOR 30 SECONDS DURING CLIMB. THE FLIGHT ATTENDANT CHECKED THE LAV AND THE CABIN. NO SMOKE OR HAZE WAS NOTED. MAINTENANCE INSPECTED THE AIRCRAFT AND PERFORMED AN OPERATIONAL CHECK OF THE DETECTOR. THE CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE. NO PARTS WERE REPLACED.