My first tantrum spiral was glorious.
I hadn't yet figured out that booze is more important than a well; but the river was in the southeastern corner of the map, while I had embarked in the northwestern corner of the map. This was a 5x5 embark, with a volcano in the middle between these two points. (40d).
My "dwarves need a water source!!" instincts told me to build an aqueduct from the river through the volcano mountain, to the northwestern corner. I was quite busy with it for a couple of seasons.
Migrants arrived. I still ignored the option to create booze; or even, in fact, to set up a farming plot. After all, the "play now!" scenario provided plenty of food, didn't it?
I guess you know where this is going. The migrants consumed all of the food and drink. Dwarves were getting hungry. Dwarves considered running across the mountain to the river to get something to drink, but the river was so extremely far away that the journey took them longer than they could survive. Dwarves were starting to become unhappy.
I continued my work on the aqueduct and to ignore the dwarves, thinking that it should be 2 z-levels deep and 2 tiles wide... for some reasons.
Finally! I breached the river. One of my miner collapsed of dehydration on the spot, the other got some water and survived the thirst.
I watched the water slowly crawl across the aqueduct. It might have been built for depressurisation, too, so that it was even slower than you'd expect.
Anyway, dwarves were dieing now. Dwarves started to tantrum and to attack the pets. The FPS dropped into the single digits.
There were insane dwarves crawling through the wood in the northwest, other dwarves smashed doors. They attacked each other.
I didn't know what to do, so I made a stockpile for the corpses, which filled quickly, and watched in horror.
Then I had the splendid idea to declare one of the sane dwarves as the sheriff. He tried to bring order into the chaos, and was slaughtered instantly. They also turned on the mayor.
A caravan came and a diplomat went away unhappily (because the mayor was slaughtered or insane). Migrants arrived happily and started to work, while the original dwarves kept slaughtering each other and chasing the remaining couple of horsies.
In the end, this new migrant wave survived. But also some of the tantruming dwarves calmed down and got back to work. They then selected a new mayor, who was one of the leaders of the revolution/tantrum. Looking at the justice screen revealed that almost everyone was supposed to be in jail for murder and destruction of property. And all of these were the new leaders of this tribe.
It was quite great, actually.