Is there also a slight slope towards that end of the driveway? This might have given that tree more water than the others, as well.
Is the soil heavy? Clay or a clay mix could be lightened up with a couple of bags of compost dug in around that tree in the winter time.
You might want to dig a test hole with a digging fork or something, out there at the very end of the bed and see if it's still soggy there. If so, you may need to try to help the tree before its roots rot from lack of air in the soil. Just aerating with a digging fork might help let the air get down to the roots.
