So in my latest fort I've decided to use a new approach to digging; making a "nerve" center of the fort near the surface layers with recreational centers, dining rooms, a statue garden/art gallery, a zoo, and some other stuff to keep dwarves happy. To the west of the nerve center I have a building district. Mason's workshops, carpenter's workshops, siege workshops, and anything involving production of items used for BUILDING stuff will go here along with their respective storage rooms.
To the east I have the crafting district; Kitchens, stills, clothiers, tanners, crafting workshops, etc. will go here. This is naturally the biggest district, and there are a lot of storage rooms underneath the actual workshops.
To the south I have the smithing industry. I took into account that I would later want to pump magma here. Usual smithing/metalworking workshops go here.
Now,
underneath the dwarven nerve center is where most of my design went to. I designated areas for channeling and digging to mark where I wanted everything. Down here is where all of the living quarters would be, with some of the noble rooms already planned out. To design the entire fort, it took at least 1 hour to 30 minutes, possibly less, but it was a significant chunk of my time.
Then, Dwarf Fortress decides to kick my groin. While my miners were excavating my designations, I stumbled upon something horrible... HORRIBLE while I was digging the stairs to the bedroom complex; ALL of my designations were eaten alive by a gigantic cavern that I unearthed! This is one cavern that I will not appreciate, even though it seems to have plentiful cave water which is pretty cool seeing I can make a well over the water.
tl;dr: A cavern f*ed my fortress design over.
Has this happened to anyone else before?