Conflicted Feelings

A life is at stake.  I didn't mean to get involved but in accidentally saving a life I put myself in a terrible personal dilemma.

I was walking home Wednesday and saw a hawk in someone's front yard.  I stopped to look at it and after a few minutes it got nervous and flew up into a tree.  What I then noticed was a rat, which was the source of the hawk's attention before I came along.

If you started from the top you've probably already guessed that the rat was alive, but it wasn't doing well.  All it was really doing was gasping for air.  I left immediately because the hawk was still in the tree and I was crossing my fingers that it would go finish what it started.  I visited half an hour later... none of the players had moved, until the hawk flew away.  Three hours later... the rat had moved but it was clearly still badly hurt.  I brought it some bread and moved her to a more sheltered location for the night.

The next morning the rat was still hanging on.  It was a little more active but hadn't moved very much.  The bread didn't show any signs of being eaten.  I'm horribly conflicted about what's in the best interest for the rat. Does it have the will to live, to survive?  Is it in pain?  If it starved, would that be a preferable way to go or should I go against my feelings and do something about it?  In my life there have been a lot of rescues, but all were much more clear cut in 12 hours.

If it's still alive I'd like to take it in and do as much as possible to help feed it even if it doesn't have much longer to live.  I'm not sure that's really a reasonable option but I can't think of many other choices.