As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6399 CMH-BDL - RECEIVED A LAV SMOKE EICAS WARNING IMMEDIATELY AFTER TAKEOFF. F/A REPORTED MILD FUMES IN THE CABIN WITH NO VISIBLE SMOKE OR FIRE. CONDITIONS CONTINUED FOR 1-2 MINUTES BUT DID NOT WORSEN, AND WARNING EVENTUALLY CLEARED. DECLARED AN EMERGENCY AND RETURNED TO THE AIRPORT AND PERFORMED A VISUAL APPROACH TO RUNWAY 28R. LANDED WITHOUT EVEN AND TAXIED THE AIRCRAFT TO THE GATE AND DEPLANED NORMALLY. MAINTENANCE TROUBLESHOT THE ENGINES. REMOVED AND REPLACED NR 1 ENGINE IAW JOB CARD CE720001. OPS CHECK AND LEAK CHECK GOOD.