The more I play, the better I get at managing a good fort, and now I am taking more risks in where I start.
After the fall of my last fort due to flooding, I started a new one in a nice area with a cool water fall. Lost 1 dumbass fisher dwarf to the fall, even though I restricted their fishing and drinking to a more stable part of the river before ever unpausing. Lost another dwarf in an unfortunate cave-in while sculpting an entrance under the waterfall, while another still was brutally mangled and died months later after succumbing to his injuries.
Rough couple of years there. But now we have a new problem; my dwarves are trapped by the vile undead, and though all the freshly slain bodies of my cattle and the wild animals top-side, there does not appear to be a necromancer. I know I did not start in an evil biome, so I don't think it could be some sort of resurrecting fog or if the necromancer is merely stealthed somewhere. None of my dwarves have been killed by the undead, and, at least with my current population, everything we need is underground, safe from harm so they can sustain themselves indefinitely.
It's fairly fresh, however, so I don't have a military other than the 5 best dwarves drafted after the siege began to clean up the undead that can safely be attacked during winter when the 3 rivers freeze, leaving only a few undead left to deal with. I also have not started the metal industry yet which is the worst of it, because we were running low on wood and I had just designated a large grove to harvest top-side when the siege struck. So we have little wood to make charcoal to start making coke with. Best option now is to dig to magma. At least there is plenty of iron and marble so I can make steel, once I have the fuel to do so.
If this fortress falls, I will come back as an adventurer and clean up the nearby necro tower before reclaiming the fort.