After a recent [CLOWN] invasion, my population dwindled from 200 to 40 dwarves. My army went from 20 elite dwarfs and 10 marksdwarfs to 2 elite dwarfs and a marksdwarf. Out of those 2 was my militia commander (legendary speardwarf lady), and a legendary macedwarf man. The commander was part of the original 7 and the mace dwarf was in the very 1st wave of migrants. They were happily married for 10-ish years.
Now, the macedwarf man had been hospitalised for 4 years (stuck in a traction bench for a broken foot and I forgot to remove him from the bench) and wasn't quite at the stage of 'Not caring about anything anymore'. He lost a fair few friends, went unhappy, then miserable, then berserk. Right in the middle of the dining hall. Killed his wife, 20 other dwarfs and was shot down by the remaining marksdwarf.
Ok, 15 or so dwarfs left, all of whom are miserable except the marksdwarf (who was the captain of the guard and had quite a lot of fun pummelling tantruming dwarfs). Queue tantrum spiral, I give the marksdwarf a silver warhammer to defend himself from the berserkers. He kills eeeevery last one of the survivors, either through law or self defence.
I abandoned. Let me recap; a dwarf went insane, killed his wife and some acquaintances, was shot by his friend the captain of the guard who then had to fight his friends and acquaintances and ended up killing them all. The entire time there was miasma and smoke seeping from the bottom of my fortress to all throughout the fort. And I also had Space Jam playing in the background on repeat. I love this game.