99 tercel starter burnt out

Hi,All:

A red warning light started to flash after I drove about 50 miles on the highway. I found the light means the parking brake was not released(But everything was fine in the first 50 miles).Then the car decelerated in a sudden. The engine or the fan was still running after I pulled the key out of the car. The dealer told me they can not diagnose this car unless they put a new starter in it. I was told the starter was burnt out. Does anyone know what might caused the starter burnt out? I am afraid that the car maybe has some other problems except the starter.

Thanks
Clark99