So.... I lost all my starting miners in the first dwarven year in ice mining incidents (It was learning curve material). But don't worry, I got more as migrants! We even were able to buy more picks from merchants. Great! We were doing really really well, until someone found a dead body, and I have to admit I made things worse by making coffins. Next thing I know, there is a Weregiraffe incident (Really? Seriously? Were-GIRAFFE? Okay. Mind your head, I doubt the dwarfs made very high roofs for you there...) and dwarfs continue, for the next dwarven month, to turn up drowned where the ice mine was.
Imagine you're a human trader. You arrive with cartloads of things, look around, and one dwarf wanders up out of a rather smelly hole (there is miasma smoking upward from the fort entrance to several levels above the ground) and offers to trade you some of the shields left lying in the sun on the trade depot floor for a few raspberries and other fruit, then wanders downstairs, never to return. There are penned sheep and yaks around you, but hey, it's nice and peaceful... hmmm.
It's the end of summer, there's two dwarfs left. One is the chief medical dwarf, walled in to the hospital, with a bad case of were-giraffe. He turned at the end of the month and killed all his patients, but not before they walled him in! The other has claimed for himself the name of Expedition Leader (who would argue? The weregiraffe banging his head in what used to be a hospital?) and he goes and drowns himself in the same place as everyone else.
And that's when migrants arrive. They find blood everywhere, a miasma pit full of water and dead dwarfs, some bemused humans at the trade depot watching some yaks and sheep they insist aren't theirs... And there's a dwarf who insists he's the Chief Medical Dwarf behind a hastily constructed clay wall covered in blood. Yep. We're leaving that wall where it is thanks.
I'm hoping they won't drown themselves.