Much discussion of Fuselage rupture/Fracture point
I would guess (small bet) that the main fracture behind the wing is in fact, at one of the "Production Breaks". I.e. one of those points where the various sections of the fuselage (which are now often manufactured in different countries) are "bolted" together during final assembly at (Renton? Showing my age!) or wherever.
Depending upon the aeroplane type or model, there will usually be a production break just aft of cockpit about L1/R1 doors area, one forward and one aft of wing (i.e. centre wingbox) and usually another just near aft doors. These breaks or junctions are default "weak" points and so most likely fracture points in accidents.
The severe tear/crack/ rupture striking through the number 3 of B737 aft of main break is probably just that. A tear or rupture.
Just my two pence worth. (Can't comment on these new fangled composite material hulls!)
SB
Last edited by Starbear; 13th Apr 2013 at 18:33.