What is your worst military disaster that ever happened to you in the entire time you have played dwarf fortress in general?
My worst was when I made what I called my first "real" working fortress. Ofcourse, it was in my clueless stage and the fortress and its workings itself was flawed. I did not know how to give people labors, thinking that if I didnt have an armorer, I couldnt make armor with the rather abundant pieces of hematite that inhabited my stockpiles. I did, however, have a metalcrafter who created metal swords for my military. At the time, I believed that until I got an armorer, I had to make do with what I had and keep my troops constantly training; I became reliant on the opinion that their training would make up for their lack of proper military dress. I ended up giving them layers of coats and cloth to atleast give them something of a uniform and make a standard equip. Later on into my military program, I believe I traded some wooden crafts for a boar leather armor piece, which I gave to my militia commander. I saw it as a status symbol for him, a ballistic vest to protect the leader. But then...
The goblins came. They came better prepared then I thought they would, with atleast 3-4 archers traveling with them. I muster my troops using burrows (Also didnt know how to use the squad screen) and they appear at the entrance. The goblins come within sight and my troops charge forward. Their archers let loose and one of my 4 sword dwarves is cut down. I quickly queue them to go back deeper into the fortress. However, my militia commander got hit, fell against a wall, and got shot at, but not killed. I've kept the thought that his armor helped him survive. Meanwhile, I take the oppurtunity of the goblins being closer to the entrance, sending out my remaining two sword dwarves who manage to cut through the goblins, their training paying off for that moment. We won, but the worst is to come. Finally, I get an armorer and we begin producing iron bars. After finishing that order, I quickly send my armorer to get straight to making iron armor. Before he was down though, the goblins came back. They were better prepared, and yet again, I send my troops up, albeit deeper inside the halls of the fortress, which turned out to be a bad move. They were far enough away from the corner that got deeper into the heart from the entrance that the goblin archers would have enough time to cut down our 3 remaining soldiers, militia commander included. I begin to panic, and I designate a new burrow deeper in the fortress, but it was too late. The goblins chased my crowds down the halls and the walls were stained with blood, vomit and floors were adorned with endless piles of guts, limbs, and the bodies of dwarves. Only one child managed to escape the fortress.