As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF SMOKE TOILET EICAS MSG ILLUMINATED POM PROCEDURE COMPLETED. LANDED AT NEAREST SUITABLE AIRPORT. FLT ATTENDANT REPORTED ODOR IN LAV AND SMOKE ALARM. AIRCRAFT WAS DE-ICED PRIOR TO DEPARTURE. RAN ENGINES IAW CRJ 200 AMM 71-00-00 FOR 30 MIN. MESSAGE EXTINGUISHED, UPON INITIAL RUN UP NOTED FAINT SMELL, BUT AFTER RUNNING ENGINES AND PACKS FOR 30 MIN. SMELL DISSIPATED AND DID NOT RETURN. NO SMOKE OR VAPOR NOTED. NO FURTHER ACTIONS REQUIRED.