The Camshaft Position Sensor (CPS) failed while driving at highway speed at dusk. There was no warning, the fuel to the engine was simply cut and the van rolled to a stop within a few hundred yards. Restarting would crank the engine, but it would not start again; not after 10, minutes, not after 30 minutes, not after 12 hours. This is a known issue with the 7.3 L diesel Powerstroke. I also knew about it but I did not carry a spare or tools, and I had not studied how to replace the sensor either.... Lesson learned.... Towing to shop was required...