I have a confession. Despite playing (on and off) since 40d, I've never lost a fort to Fun. Usually, I always quit out of boredom and go play adventure mode instead. Well, it finally happened. My current fort, "Deathfloors" had finally tasted true Fun. A siege arrived and I had to face them because a tantruming dwarf had destroyed the lever that shut the floodgates of the main entrance. A whole bunch of soldiers were killed and shit hit the fan. Soon after that, everyone had a flashing red arrow, dwarf were going insane, children were going berserk and beating their parents and everything was getting destroyed. The murders/executions of berserking dwarves was the first wave of death. After that, a whole bunch more died from dehydration due to being stark raving mad (or babies having their mothers die).
Now, my population of 200+ has been reduced to 50-something (most of them children). There is barely anything left of the military, all of the industries are gone, I'm struggling to bury everyone, there is junk everywhere, THE DINING HALL IS FULL OF DEAD BABIES and overall, its not a very fun (but very Fun) time we're having over here. The only luck is that a tantruming dwarf broke a trade depot while human merchants were in it, so I kinda ended up stealing all their stuff by accident. Hopefully, that should keep my food supplies stocked while I get some new farmers.
Sooo, yeah...