My Sister's Keeper

My Sister's Keeper - Jodi Picoult Such a beautiful story. Much much much better than the movie. The ending really left me crying..

*SPOILER ALERT*

I feel like comparing the book with the movie-adaptation. Why was it that in the book, Anna was the one who died, but then in the movie, Kate died and Anna lived? I think it would be much more heart-breaking and people would get shocked if they followed the plot-line on the ending of the book. Then, the people would see an ending that's quite different from the usual.