Excuse the long narrative here, but I've always been a bit of an obsessive storyteller. ^^'
This was back in v0.28.
(EDIT: by that I mean 40d. ^^')
Having started one of my fortresses with a slow and incompetent miner, I accidentally managed to get her to channel a tunnel into a aquifer on the map I had embarked on. Needless to say, she drowned. I wasn't put off though, and proceeded to build my fortress above ground, next to the coast. My carpenter spent most of his time building the 'lower class' buildings early on, purely from wood, but after I had a mason come through and the town hit 50 inhabitants, the need for noble buildings with stone walls arose. No biggy, I kept to my usual outdoor design of 'stone walls, wood floors'. My carpenter, who had had a long break, was now a grand master and had made hundreds of beds in his 'time off'.
It was partway through the third year, and having been on an island all this time with little in terms of goods being produced, immigrants were coming slowly. I had hit about 65 dwarves by now, and all seemed to be going well. I had prepared a grand extension to my dining hall, by refurbishing the lower level into a group of kitchens with a central stockpile for produced food, and converting the basement into a large stockpile completely for the use of foodstuffs ready to be used for the kitchens. Above that, would be a tower of suitable dining areas, with a large central opening that allowed dwarves to look down directly into the kitchen. It was a megaconstruction within the megaconstruction of the actual fortress (which was built to look like a medieval castle), and was built around an idea of mine for 'the ideal restaurant'.
Part way through the construction of the roof, and after a large influx of migrants, I decided to expand it upwards by another floor. Hence, the central section needed to be removed, to keep the feel of the building. I ordered the centre of the roof to be dismantled, and the 30 idle peasants of the time immediately rushed to the building to dismantle it.
Of course, 30 dwarves trying to dismantle the same area of flooring is not a good idea. And so I found out.
The dwarves who arrived first began to dismantle their tiles, and then others came in, standing on tiles that were being dismantled, to try and dismantle their own.
It was a spectacular performace, I think. 30 dwarves went to the roof that day, only 13 came down. The others all lay in crumpled heaps in the centre of the food stockpile, crying out in agony. Because of my severe bucket shortage, and the fact both of my carpenters (including the grand master) were lying with broken legs in the food stock pile, only 5 of the dwarves who plunged through that hole actually survived.
And the most unfortunate victim? Poor little fluffy, the resident kitten, had a falling section of the floor hit her on the way down.
As of the future of that fortress, the fort was later abandoned when the bronze colossus who had taken residence on the other side of the island got a bit sick of his noisy neighbours, and went on a rampage, sneaking in through the hole in the wall in the noble quarter. The poorly trained castle guards and quickly drafted militia became either snacks or toothpicks, and the colssus went on to kill 50 something of the 90-odd fortress residents of the time. And he destroyed the stills. Meaning no more booze. Having never actually been killed, the colossus remained in the ruin for a full year, hanging around the well in the centre of the noble district. Booze stockpiles dwindled, and eventually it became obvious that all my dwarves would die of thirst. On the 14th obsidian, 16, the dwarves abandoned that fortress for good.
The save file was later lost when I formatted my harddrive to make way for a new operating system... Sorry guys