As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BTV - FLT 4208 - AFTER TAKEOFF, THE MAIN PASSENGER DOOR WARNING LIGHT ILLUMINATED. AIRCRAFT RETURNED TO BTV AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED DOOR AND FOUND THAT HANDLE WAS NOT PROPERLY CLOSED. AIRCRAFT WAS RETURNED TO SERVICE. (M)