As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - THE SMOKE ALARM IN THE LAVATORY SOUNDED, IT RESET ITSELF AND NO FUMES OR SMOKE WERE NOTED. UPON INSPECTION, FOUND APU OIL SEAL LEAKING, ALLOWING OIL CONTAMINATION VIA THE BLEED AIR SYSTEM. PLACED APU ON DEFERRED MAINTENANCE LIST AND REPLACED AIR CONDITIONING WATER SEPARATOR SOCKS. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.