I'm playing from a custom start.
My embark area was in a "Temperate" biome. My party of Dwarves, with their equipment and livestock, started the game right on top of a frozen river, with the Wagon straddling the edge of the bank. The instant that the clock started, the river melted and dumped most of my Dwarves, all of the livestock and the majority of the supplies and equipment into the water.
Thanks in part to one level of Swimming ability, all of my Dwarves survived, and even emerged on the same bank of the river. All of the livestock and poultry made it to shore... although many of them are on the wrong bank. I can deal with that, though. The big problem is the supplies...
ALL of my Plump Helmets and ALL of my seeds are on the bottom of the river... along with my Anvil, one Axe, two Picks, the bulk of my food, NEARLY ALL OF MY BOOZE and much of the other equipment.
There are a few rays of hope, though. I still have one Axe and a couple of Picks. The Magma layer is only about 40 levels down... a very lucky break, since it might just as easily have been 140 levels... and while this is an Aquifer map, I think that the Aquifer is off to one side, rather than directly below me. There are enough plants around that I can set up a Booze assembly-line, and perhaps make some Prepared Meals to sell to the Fall Caravan.
It's going to take me ages to build a Pump Stack to bring up the Magma so that I can cast a dam. Hopefully my Dwarves will be able to survive until the Caravan arrives, after which the logistics of the situation will become somewhat simpler.