If your coil is dead the car will not start and obviously if it dies while underway, the engine will stop.
Your car restarted later and I suppose it's possible the coil is getting tired. Unfortunately, you could have any number of things wrong in either the ignition or fuel circuit.
I want to say that I read a post by Larry Bible a few months back that sounded similar to your situation.
You might check thru the archives. Perhaps it could be of help.