Kerrville, Texas — With more rain on the way, the risk of life-threatening flooding was still high in central Texas on Monday even as crews search urgently for the missing following a holiday weekend deluge that killed at least 82 people, including children at summer camps. Officials said the death toll was sure to rise.

Search teams plodded through mud-laden riverbanks and flew aircraft over the flood-stricken landscape of central Texas for a fourth day on Monday, looking for dozens of people still missing from a disaster that has claimed at least 78 lives.