To put it simply, some of the dwarves are trying to do tasks that they can't do for some reason, and thus are just standing in place, unable to do anything as they slowly die of dehydration and starvation. Not only that, but as I let the game play out past the initial three dwarves dying of dehydration, more dwarves started dying of dehydration. Turns out that some of the working dwarves are doing nothing BUT working until they die. I don't know why this is happening and I hope this file will be able to help you or anyone figure out what the problem is. The first few things you'll need to do is remake the study for the bookkeeper so you can see how they react to trying and update the records, along with one of the miners that suddenly decide to go hunting for small creatures and the dwarf trying to attend a meeting in the stone stockpile floor. Also Quick Notice, this is a save from the Steam Release of Dwarf Fortress, so if there's possibly any problems to be had with booting it up in general, I apologize. Best of luck with solving the problem and I hope that my save game won't be corrupted if there comes a patch that fixes this issue, I like my current fort alot.