Never had as quick defeats as these guys, but the quickest one yet was just earlier today (not counting those games where you leave instantly. That's not losing fun, that's just being picky about locations).
About an hour. I'm still somewhat of a newbie at this game, so most forts have so far been borderline-paranoia safe with death by FPS or HFS exclusively. Never embarking without multiple metals, never on an aquifer, never in evil territory. Been using the danger room exploit ever since I heard of it. The most advanced mechanical thing I've ever done was a colloseum with a plethora of levers and drawbridges.
Today, I was stupid enough to think I could consider myself a veteran. So I embarked on a completely flat terrifying glacier, with an aquifer. Lost my one soldier within a few minutes to a zombie polar bear, the rest managed to dig in within the underground igloo I made in the meantime.
From there on, I simply had no idea what to do at all. Digging the stone anywhere below the ice layer just revealed water, so no stone for me. No wood either, except for the three from the wagon. No place to farm, barely any life on the map... I lasted about an ingame month before I realized it was completely hopeless for me.
Back again in the safety of my old fort. Definitely going to try that again, though, because it was a lot more fun than the huge ass megaforts with ~10fps, 250 dwarves and too much metal to handle, that I usually do.