I suspect most of the bodies are buried in the sand from the flash floods, under piles of trees and even high up in trees. some will not be found
I saw one video of a search of six miles of a stream, they had 100 marked targets indicating death, none of which they could actually exhume to determine if it was a human or an animal so the target was marked for later recovery,
When whole families and whole settlements are wiped completely off there is no one to report them being missing or unaccounted.