Moccasin will be in my thoughts. I know what its like to see an animal take its last breath, and its truely heartbreaking.

Do you know whats causing these deaths?
Just wondering, do you quarantine your birds? A newer bird may have brought in a sickness without you knowing.
Of course, this is only a guess, as I don't know as how your other birds are acting.

Either way, best of luck to you and moccasin. Again, she'll be in my thoughts for a quick and relatively painless passing.