As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6378 CMH-RSW RECEIVED LAV SMOKE EICAS WARNING ABOUT 700 FT AGL AFTER TAKEOFF. DECLARED EMERGENCY, COMPLIED WITH QRH PROCEDURES. FLIGHT ATTENDANT REPORTED AN ODOR IN THE CABIN AND A LITTLE HAZE, BUT NO VISIBLE SMOKE. HAZE CLEARED AFTER 2-3 MINUTES. RETURNED FOR ILS 28L LANDING IN CMH. MAINTENANCE REMOVED AND REPLACED THE LAVATORY SMOKE DETECTOR AND THE SMOKE DETECTOR PANEL. PERFORMED TEST FLIGHT. NO DISCREPANCIES NOTED.