As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6410 CMH-BOS - ON TAKEOFF ABOUT 1000 AGL, LAVATORY SMOKE BELL WENT OFF. F/A REPORTED THAT THERE WAS NOT ANY SMOKE IN THE CABIN. DID NOT DECLARE AN EMERGENCY. AIRCRAFT RETURNED TO THE FIELD AND LANDED WITHOUT INCIDENT. PASSENGERS WERE NOT PREPARED FOR AN EMERGENCY EVACUATION, AS THERE WAS NO SMOKE, AND NO REASON TO SUSPECT A FIRE. REMOVED AND REPLACED LAVATORY SMOKE DETECTION PANEL AND LAVATORY SMOKE SENSOR. RAN ENGINE AND COULD NOT DUPLICATE.