As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - CREW REPORTED LEFT ENGINE OIL QUANTITY LOSS. EMERGENCY DECLARED FLIGHT RETURNED MIA LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND B-NUT ON OIL PRESSURE LINE ON BOTTOM OF OIL PUMP LOOSE. TIGHTENED B-NUT. SYSTEM GROUND CHECK NORMAL OPERATION.