It was a book, but not nearly as good quality as Krakauer, I wish he had more books, his style is awesome and takes an already interesting story to a new level.
SPOILERS ABOUT GRIZZLEY MAN BELOW!!!!!!!!!!!!!!
So yes, he and his GF both get eaten alive, they fought for 6 full minutes with the bear that devoured them. All caught on audio, but the dude didn't get the lensecap off the video camera so now footage. It was brutal, but its the whole backstory that makes this interesting.
Dude lived with these bears for 13 summers. Most people realized he was a nut and his death was only a matter of time.
Great movie though, very well done. A must see in my opinion and I don't say that often.