As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING FLIGHT THE LAVATORY SMOKE DETECTOR ACTIVATED AND SMOKE BECAME VISIBLE IN THE CABIN. THE CREW DECLARED EMERGENCY AND LANDED SAFELY ABOUT 30 MINUTES LATER. EMERGENCY SERVICES DID NOT FIND ANY TRACE OF FIRE OR HEAT. MAINTENANCE FOUND OIL LEAKING FROM THE NR 4 BEARING HOUSING ON THE NR 1 ENGINE. THE ENGINE WAS REPLACED.