As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6450 IND TO CVG - DURING CLIMB-OUT, A LAV SMOKE WARNING MESSAGE BRIEFLY APPEARED ON EICAS. THE FLIGHT ATTENDANT INSPECTED THE LAV AND FOUND NO EVIDENCE OF SMOKE OR FIRE. THE CABIN GASPERS WERE MISTING SLIGHTLY PRIOR TO THE INDICATION. INSPECTED LAV SMOKE DETECTOR AND FOUND EXCESSIVE DUST IN THE UNIT. CLEANED AND TESTED LAV SMOKE DETECTOR WITH NO FURTHER DEFECTS NOTED. OPS CHECK GOOD IAW EMB 26-14-01.