Utterly Mad

If you mine out a natural cave-in the body will be there, whereas if the instadeath was due to a constructed wall falling, the body will remain exposed due to the falling construction reverting to an item on landing.

Meanwhile...Kobold Kamp again. Making a less dwarfy sort of artificial cave for them, but still using the untested hatch method of hopefully deterring building destroyers. Seems just hollowing out large spaces to pack workshops, stockpiles, and furniture is way more space-efficient that my "grid of 5x5 rooms" method of digging out dwarf forts.