I don't talk much about religious things on the internet, but I'll make a special exception for you and your son-in-law, DG.
Remember that God has forseen all of this, and has arranged for all of it to happen for a reason. He has sent this challenge in order to provide the best (spiritual) benefit possible to Jason, his wife and family, and to you and your wife (and others around). The only thing you get to take with you is your experiences in this life, and this experience has made each of you a better, stronger person, with greater love for Him.
Rest assured that Jason (and Blake) are very much alive, and healthy, pain-free, and happy. And that both of them, knowing what they now know, would choose to go through it again, because of the good that came about because of it. God loves you, and you need only trust Him, that He will make everything work out for the best in the end.
Our condolences on your loss, and remember that we love you,
Spott