On one of my latest forts I was trying to go for the whole, "collapsing the world thing," so I started with seven miners. Now as I was going along on my map, my miners kept being interrupted by creatures, so I temporarily would turn them into military to take down the beasts. Now one time one of my dwarves was busy dispensing with a group of turkey vultures and had killed quite a few when one got a lucky shot, pierced his heart and he died instantly. Later on the same fort I had another dwarf that was chasing beavers. Now, beavers can swim, but the dwarf could not, causing him to drown when he chased the beaver into the river. Because of these two deaths, one of my other dwarves became quite melancholy, and then went insane, running around and tearing his clothes off. Shortly after this dwarf goes insane, my expedition leader throws a tantrum and kills the insane dwarf in a fist fight. Then, Another of my dwarves went berserk, killing another dwarf and then chasing my horse around the map. There was a period of time then until the horse ran back into my encampment and then hit the berserk dwarf in the head, knocking him unconscious. I then commanded my leader to go and quickly finish him off. My leader then walked up and hit him over the head killing him. My leader at that point had killed more of my dwarves than she had killed natural creatures. Shortly after killing the berserk dwarf, the guilt drives my leader insane, who then starts running around babbling. This then meant that I had only one dwarf left, so I continued on my goal to collapse the world. About one year later, the last dwarf channeled out the very ground beneath her feet, causing a deathly fall of about 7 stories.
So all in all, of my seven dwarves I had one die fighting turkey vultures, one drown chasing a beaver, one go insane and then be killed in a fist fight, one go berserk, killing another as he escaped, another go insane from the guilt of killing the berserk dwarf, and then my last one suffering from a deathly fall caused by her own stupidity. Ahhh.. Good times.