Fuselage Breaks
Think about how an aircraft is built. The strongest bit is the wing box - by a considerable margin - for what should be obvious reasons. So if you over stress a fuselage to failure, it's not initially going to break at the strongest part - it'll fail fore and/or aft of the strongest part. So if a fuselage breaks into three parts, it's logical and perfectly understandable that it'll break for and aft of the wing.
It's not poor design or construction - it's basic physics.