> People can live over 60 days without food, so maybe that part isn't so unexpected

It's not a physiological problem. It's a psychological one. When you ate everyday all your life, not eating is scary.

> I believe after 48 hours severe dehydration sets in...after 3 days...kaput.

You can live more than 3 days without water. Either with training, of because the conditions help (you don't move much, temperature and humidity are favorable, you don't eat, etc).

There are cases were human lived for 9 days without water.

But they had water near them so that was out of the equation.