As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL - LEFT MAIN LANDING GEAR WOULD NOT RETRACT ON TAKEOFF. EMERGENCY DECLARED, RETURNED STL WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT MAIN GEAR RETRACT SUPPORT FITTING AND LEFT MAIN GEAR RETRACT CYLINDER AND CYLINDER LINKAGES. SYSTEM GROUND CHECK NORMAL OPERATION.