1997 Ford Escort Dash, Lights and engine died on highway.

I have a 97 Ford Escort that has had a new battery installed within the last 12 months.
Yesterday, the battery warning light came on during the day, but then did not come on during the evening.
Today, the light came back on during the day. The car was started 4 times today.
After the last start, about 5 minutes into the drive, systems started failing. The radio flickered out, lights died, the speedometer stayed at 0mph, but the engine kept running. Then after about another minute, the car stopped accelerating and the car slowly drifted to a stop as the engine stopped producing power. At that point there was no power in the car at all.
Any ideas as to what would cause all of these things to fail at once?