I was driving down the road on my way home when the engine suddenly (for no discernible reason) shut off. I was able to maneuver it off the road and into a parking lot. I tried to restart it, but that didn't work. It would turn over, catch, then stutter and turn off again. There is over half a tank of gas in the car, and the battery cables aren't loose or anything. I flipped the fuel pump switch a few times (located under the dashboard on passenger side) but that didn't help with restarting. Puzzled as to what could be wrong.