So just minding my business, when 68 invaders WITH FLYING MOUNTS, (though a few cave crawlers but mostly giant bats), trolls, and multiple weaponlords, all come rolling into my tiny 2x2 embark. A series of ridiculous events leads me to accidentally killing all of them without losing any supplies or so much as bruising anybody's fat (except for one mason killed) despite the fort being set up with absolutely zero defenses. All I had was one squad of iron fighters, which I didn't have to use.
The events of the day:
1) Every single invader for some reason rushes not to my dwarves, but to my graveyard, and sits there for 3 minutes or so desecrating corpses and leaving me alone. I have time to get every single dwarf into the one room I can seal off.
2) The main stairway is elsewhere, and has a 2x1 hole at the top, which is my only weakness. So I command two people to wall it off, and mine my way over to it, hoping they can run up and seal it quickly, and I can take over my base and later on get rid of the invaders.
3) Doesn't go as planned. I get one wall segment completed, but then all of the bats start rushing through the remaining hole and chasing my mason. He runs down into the depths of my newly uncovered fort. Either to get away or to grab a stone for the next wall, I'm not sure?
4) In the meantime, one of the invaders was a building destroyer and while waiting in line to go rush the mason, OF ALL THINGS, decides to destroy the floodgate leading to my main magma supply line near the top of the stairs.
5) Their entire army is now chasing one guy down the stairs, and they themselves opened up an entire volcano leading straight down the same stairs. A hundred goblin voices scream out in terror.
6) Due to having just breached the cavern level not 5 minutees before, I hadn't sealed the bottom of the stairs yet, so all the lava will drain into the caves, thus not flooding my base or any of my supplies.
6) My dwarves sit down on the steps, scratch their heads, roast some plump helmets, and think about the engravings they will make of this later...