You didn't give a lot of detail so I will comment on two scenarios:
If the dash stayed lit up and heater blower running, everything else normal just engine stopped running during this event then it certainly sounds to me like an electrical issue on the engine. Has anyone recently been under the hood working on it? Maybe some work to the FICM, PCM, IPR, can sensor, crank sensor. It kind of sounds like a loose connection at one of those areas.
If everything went dead then I would start checking right from the batteries and work my way into the electrical system. There is a red aprox 4 gauge wire coming off the drivers side battery...it runs ALOT of of stuff, you might want to take a look at that.