Why the fuselage broke down
The fuselage was going up the slope of the blast wall. At this moment
there was not a lot of deceleration as the plane was only pitched
around the CG.
A short moment after the Cockpit area went over the edge the main
gear started climbing the wall. At this moment the whole plane was
slowed down quite heavily because now there was real deceleration.
This created a forward-down momentum around the CG. This momentum
smashed the forward fuselage on the sharp edge of the blast wall cutting
it through up to the main deck. As the integrity of the lower part of the
fuselage was completely destroyed the down momentum bend down the
part of the plane forward of the edge.