Bits of submersible with dead billionaires? Sand formed by the sudden and thorough crushing of a submersible with dead billionaires? The Logitech F710 aught to be mentioned as well. Of all the things cheap game controllers have suffered, utterly destroyed by deep sea pressure is one.

Also the majority of it has been recovered and brought back up. The hull and billionaire bits are back on shore somewhere.

A small lump of metal, glass, bone and maybe a little goopie bits if they got trapped does not elicit the same mental image.