Why did my van loose all power and now won't start

What is your question?

I recently replaced the starter in my van. After doing so I started it and began to drive. About 5 miles later I list 100% power (lights, engine, EVERYTHING) while driving. After pulling to the side of the road I tried to start it but all I get is a click. I checked the the grounds, the alternator, replaced the battery, the starter solenoid and relay, and checked all fuses. Why did I loose all power and now I can't start it? Oh and no the motor did seize.