As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#371, LGA-FLL. 'TOTAL NAV FAILURE FROM MCDU, ALL NAV FIXES DISAPPEARED FROM ND. A/C WOULD NOT ROLL OUT ON HEADINGS. A/C WOULD NOT GO DIRECT TO ANY FIX. NO NAV DATA EXISTED. ROUTE SHOWED A FLIGHT DISTANCE OF 4773 NM, EVEN WHEN ALL FIXES WERE REMOVED MANUALLY AND THE FLIGHT PLAN REENTERED. A/TH INCREASED A/C UNCONTROLLABLY DURING DESCENT AND HAD TO BE DISENGAGED; REMOVED AND REPLACED FMGC #2 PER AMM 22-83-34. AFS TEST OF BOTH FMGC'S ALSO CHECKS OK PER AMM 22-96-00.'