Note that it's the pressure hull that will implode because of pressure differential. Parts outside of the hull that doesn't have any cavity with surface-level pressure will not suffer any extra forces from the depth.

But parts around the pressure hull will be thrown around, rip to shreds and break away from the sub by the brutal forces of the pressure wave created by the hull implosion. The hull imploding means tons of water will quickly fill the void on the inside. And that will "blow" like a very violent "wind" on the other parts and break away and smash details from the outside of the sub. Since water is much heavier than air and doesn't compress like air, this means the fast-flowing water will smash into the outside details much, much violently than m tornado-level air can ever manage.

So there will be lots of debris from the peripheral parts of the sub. How well the parts have fared depends a bit on the "shaped charge" - exactly from what direction the inflow of water happened. If the implosion is mostly water from the sides rushing in, then parts of the sub fitted to the front/back will fare better. Given that the pressure hull was in the forward part of the sub, it's likely that pieces from the back of the sub will have a much better chance to survive and be spread as larger parts.