Death #2

Okay, so by now everyone knows that the Grandma is dead. Is the fact that both old people that came to California died symbolic the fact that they were a part of the land they grew up on, an extention of the preacher's description of the grandpa when he died (that he was already dead when he left Oklahoma), or simply the author underscoring the difficulty of the trip by killing off the old people.

Oh, and take a guess: who, if anyone, is going to die next??