Sad story, but when I get old I'd much rather pass away like him than in a hospital bed.

Originally Posted By: JohnN
I'm wondering if he had a heart attack or something.


Certainly a possibility.

Originally Posted By: JohnN
It seems odd that he was on the radio, then no response, then they find him the next day basically dead.


Maybe a bit odd, but perhaps not so much if you take into consideration all kinds of trouble you can have with radio communication, in particular if you're away from totally flat terrain.

For all we know, he might even have turned off the radio to save batteries.