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.

The death toll now stands at 70 in the wake of torrential rains and the resulting flooding in Texas. By far the greatest number of fatalities occurred in Kerr County, where 59 people are believed to be dead, according to officials, including 21 children.