What would cause an 04 Tahoe LT to die and not restart while driving down road won't turn over either

Can be caused by many things but i would start by checking fuel filter and fuel pressure

Check battery and alternator

you need to check your fuel pump pressure sounds like it losing presuure

If it died and won't crank, sounds like you lost power to something.
Does the warning lights come on when you turn the key on ?
Got headlights ?
A mechanic would check for voltage at the starter and work back from there.

Possibly a crankshaft position sensor had the same problem with one of my former vehicles. Be careful buying a new one though it is an electronic part and it is not returnable at most part stores. That is what it sounds like to me though.

Well, I would try to check the spark to make sure the ignition system is providing spark to the spark plugs. Then, I would check fuel pressure, to make sure that the injectors are getting enough pressure to provide gas to the cylinders, using a fuel pressure gauge on the rail.

bet on the fuel pump and old filter

alternator is going be the problem, when that stoped working the car was running off the battery when that died your car cut off.

a bad crank sensor causes a car to shut down while driving down road. and will not start back up for about 10 minutes. have car scanned to read the problem codes. any auto parts stores will scan for free.

sounds like an Ignition control module,check for spark immediately after it dies.the spark should should be strong even up to a half of an inch gap