I notice that many posters tend to peel the onion way too deep in discussing how and why planes are designed to break apart.
The investigation is still wide open to a myriad of possible causes some remote and some more probable. As debris is found and analyized by the Airbus structural experts the probability increases or decreases for the various theories. But they will remain as theories (using up all kinds of thread pages in this forum) until/(unless the main wreckage on the bottom of the sea is found and photographed.
Thus most of the effort in examining the recovered pieces is to get clues as to where the big stuff lies on the seabed. So I would suggest to devote more speculation, if any, to that end since we really need more hard data or we are just filling these pages with the same old rehash.
let's see how long this post lasts