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.

Devastating floods across central Texas have killed at least 51 people after a storm pounded the region. Texas Gov. Greg Abbott issued a proclamation declaring Sunday as a day of prayer across the state in response to the flooding.

Before heading to bed before the Fourth of July holiday, Christopher Flowers checked the weather while staying at a friend’s house along the Guadalupe River. Nothing in the forecast alarmed him. Hours later,