As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - CREW REPORTED GEAR DOOR OPEN LIGHT REMAINS ON WITH GEAR RETRACTED. EMERGENCY DECLARED FLIGHT LANDED ORD WITHOUT INCIDENT. AIRCRAFT LANDED WITH BOTH MAIN LANDING GEAR DOORS DOWN. AIRCRAFT REMOVED FROM SERVICE. FOUND LEFT GEAR DOOR MISSING TARGET/SENSOR AND BRACKET. REPLACED TARGET/SENSOR. SYSTEM GROUND CHECK NORMAL OPERATION.