Definitely the tail section. Compare the two photos for some of the ports. Additionally, if you compare the paint scheme of the old NWA design and the accident photo, they match fairly well.
Plus, it seems as if on the left side of the accident photo, that the engine pylon is stil there, but the engine is missing.
It does look likea cockpit, but the "windows" don't match CRJ windows. Plus they'd show definite signs of breach with the amount of damage with what the "nose" section looks like.
But that's just my opinion... I'm not really one to monday morning quarterback a smoking hole ("schmokin' hole" if you were ever a Craig Funk aviation safety student).