The fort: Etes Mezum, "Blow the Smoke". The year: 505, spring.
One year ago, goblin ambushes began. We were a small fort of 18 dwarves (popcap 15, I want a generational fort), but our military was well-trained. The ambush was discovered by Ineth Abanrigoth the Chopper, our militia's co-leader. Her first move was to lop the nearest goblin's arm off. No goblins survived.
Unfortunately, a second ambush was discovered by the elves and most of them were massacred. Oh well, free caravan loot.
This year we didn't fare so well. As the first elves reached the depot (on the north side of the fort), so did the first goblins. Our military dealt with those easily, but another ambush was discovered on the southeast side of the fort by the rear of the elven caravan. One of our potters was going southwest to get water and discovered a third ambush almost immediately after the second.
Blow the Smoke is a large, circular above-ground fortress around a volcano. Ineth went around counterclockwise. The rest of the military went around clockwise. Ineth jumped right into the middle of the third ambush and was killed almost immediately. The rest of the military cleaned up the second and third ambushes, but not after the potter, a farmer, and some elves were killed.
The fort is recovering slowly. We've launched some new projects aiming to help them, such as a huge dining room for them to forget their troubles in and a burial chamber so the dead can be put to rest. There are also some targeted at avoiding tragedies like this in the future, like a reservoir so dwarves don't have to leave the fort to get water. We will survive!
edit: Maybe we won't. One season later, three more ambushes. All the non-injured military is dead now.
edit: I am live-editing this tantrum spiral. Miner goes berserk, gets killed by human caravan guards. Wounded soldier goes berserk, kills other wounded soldier, gets killed by human caravan guards. I have eight dwarves left. One of them is a wandering motherless baby that's about to die, another is a wounded soldier that's still laying in the field because nobody wants to carry him to the hospital. My trader is running around babbling.
edit: The last potter has been stricken with melancholy. I have two adult non-insane dwarves left. I'm sealing off the fortress.