The 64 Dollar Question is why did it crash in Tennessee....if it was routing from Enterprise, Alabama?
The news articles have not identified the point of takeoff as far as I can tell....so until that is known for sure....routing questions will have to be held.
Was it fuel exhaustion or starvation....two very different issues.
Bad Weather in the area....and trying to scud run and thus going far slower than planned maybe?
Lots of speculation can be made with the scant information available.