Might as well prepare yourselves for the next 10,000 posts on this subject.
If they don't find any part of the airplane how many reasonable theories will be left ?
If they find only surface debris how many reasonable theories will be left?
If they do-not or can-not recover the black boxes but do find the aircraft on the bottom, how many reasonable theories will be left?
When considering what is a theory also give a thought to a possible viable corrective action, else the theory is worthless to even set forth inside our aviation community.