As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3011 - PHL-ROC - AT APPROXIMATELY 300 FEET OFF THE GROUND, RECIEVED A -LAV SMOKE- EICAS MESSAGE FOLLOWED BY A TRIPLE CHIME ALARM. DECLARED AN EMERGENCY. NOTIFIED FLIGHT ATTENDANT AND VISUALLY CHECK THE LAVATORY FOR SMOKE OR FIRE. FIRST OFFICER RAN APPROPRIATE CHECKLISTS. FLIGHT ATTENDANT FIRE WARNING HAD ALSO GONE-OFF, BUT THERE WERE NO SIGNS OF FIRE OR SMOKE. NO SIGNS OF FIRE OR SMOKE WERE TO BE FOUND. MAINTENANCE REMOVED AND REPLACED LAVATORY SMOKE DETECTOR IAW EMB 145 MM 26-14-02/401. OPS CHECK GOOD.