Problems starting followed by sudden death

[trilobite]

So I've been having an issue that started recently where after driving for a reasonable amount of time (say, 10 minutes to the grocery store) I would park the car, and when I would come back out after 10-15 minutes the car would not start. This doesn't seem to be an issue with the starter, but it was acting like it wasn't getting fuel.

This only started after the weather became warmer, and never has a problem cold starting, ever. This has happened about 6 times total now. It is predictable, so it hasn't been a huge issue.

As a teacher, I am off for the summers, so I was waiting until next week to crawl under it and start to diagnose the fuel system. Then came this morning. I was driving into work (which has been fine because the car sits all day before I drive it again), I stopped at a drive-thru to get breakfast, and the car literally just stopped running. No sputtering, just full stop. There was no electrical interruption or anything of the sort, the engine just stopped running suddenly.

Now this has me concerned that my fuel pump/fuel filter/fuel pump relay guesses are not the actual problem. Has anyone else encountered a similar problem?