My bone carver was minding her own business, decorating random crap with bone and shell, when some random peasant went fey and kicked her out of her Craftsdwarf's shop.
The peasant demanded a whole bunch of things that I didn't have, like (giant?) cave spider cloth, rough gems, and crystal glass, so he just sat there for a few months until he went melancholy and threw himself into my well.
My bone carver went back to work. About a month later, some random immigrant who had literally just arrived became possessed, and seized the workshop. Evidently, he needed some kind of black cloth. Needless to say, I was unable to procure the cloth, so he went berserk and was taken down by the fortress guard.
The bone carver went back to work. A month went by, and another, without incident. However, about two seasons later, yet another peasant was taken by a mood. Guess what workshop he went for?
Wrong! The dwarf was taken by a FELL mood, and proceeded to slaughter a nearby child. Incidentally, the child belonged to my bone carver! The peasant then proceeded to make a dwarf leather glove out of the remains. (Which was shortly thereafter stolen my a Rhesus Macaque.)
What happened next? Well, my bone carver was devastated by the loss (and she really wasn't happy in the first place) so she went melancholy. About a month later, she followed the first peasant and cast herself to a watery grave at the bottom of a well.