What was found
MASTER CAUTION ILLUMINATED. FOLLOW BY A/C YAW AT 33,000. LEFT ENGINE SHUT DOWN (AUTO) SUDDENLY. RED BOXED NUMBERS WERE VISIBLE. OIL PRESSURE AND OIL FILTER LEVEL 2 ALERTS WERE ALSO NOTED. CHECKLIST WERE ACCOMPLISHED FOR ENGINE FAILURE (FIRE BOTTLE WAS NOT DISCHARGED) AND THE A/C LANDED WITH LEFT ENGINE SHUTDOWN, WITH NO FURTHER PROBLEMS. (MX SAID IT WAS GEARBOX FAILURE.) CORRECTIVE ACTION: REMOVED AND REPLACED NR 1 ENGINE.