"And how do you give the person dignity in death "
Sorry - in emergencies with massive deaths - dignity is a mass funeral pyre. The only medically sound choice.
The only other choice would to give some practical use to the Kennedy/Kerry "Big Dig" in Boston.
Place all the bodies in there and seal it. Save money!
In times of natural disaster, dignity is a luxury that doesn't exist. "Dignity"? It's an absurdity to even raise the issue.
As much as possible the bodies should be treated with prudent respect, and identified if possible. Beyond that, the living should be the focus of concern.