1998 Saturn SC2 Complete shutdown while driving!

After some warnings which included while tapping brakes the dashboard lights dimming, the charge light appearing off and on, clock light went out, slowly but surely, the symptoms increased and just got worse. I took it to a Saturn dealership and had it looked at. The mechanic told me that the alternator was holding the maximum charge, checked all battery terminals and wires. Couldn't find anything. This was a mistake as 3 weeks later the charge light came back, stayed on for 2 days straight. After that one night driving down the freeway, all warning lights on the dashboard started to flicker like a Christmas tree. The engine started to stall and I had to ghost ride to an exit. Upon stopping the vehicle, it froze and died. What happen that a Saturn mechanic could not find?