There is magma pipe in the lower left corner of a 6x6 map. There is an underground river (and the only river in existence) at almost the upper right corner of the map, about -10zts (negative ten zee levels to surface). Going to breach the river so I can get started on my various projects. 'Machine', the head dwarf and a pretty damn good miner, goes half-way across the map to take care of this (I had dug a vertical shaft near the river for this purpose, with no connection but overland to the fortress proper). I was breaching at the wrong Z level. Against all odds, due to the slightly bizarre construction of the shaft (the horizontal section was on two z levels and zigzagged between them), he managed to haul himself up the stairs when the water rushed in and escape his gruesome death. It all happened so fast I completely lost track of him. Fortunately, I built a wall where some of the river creatures might gain access, and am now working on completing the irrigation system, which will require me to risk another dwarven life, as they need to carve a fortification into the only thing between them and a wall of water. I can only hope he makes the same daring escape.
Also, the place is being ravaged by a neverending (hyperbolically speaking) stream of skeletal caveswallowmen. My 4-dwarf military is composed entirely of wrestlers. So far the mortality rate is 20%. That is, one in five civilians who gets task interrupted by cave swallowman dies. In a stroke of genius greed and stupidity, I am setting up traps at random locations throughout the main beast pathways. This won't stop the cave swallowmen but it will keep the elephants out of my beard. Incidentally, the merchant and immigrant slaughter is quite lucrative.