HUNT, Texas — As the search in Texas continued Wednesday for more than 160 people believed to be missing days after a destructive wall of water killed over 100 people, the full extent of the catastrophe had yet to be revealed as officials warned that unaccounted victims could still be found amid the massive piles of debris that stretch for miles.

Emergency officials are starting to focus on alert systems as they search for answers about how the flash flooding swept away so many.