Multiple urban search and rescue teams from across the country that responded to the deadly floods in central Texas told CNN they were not deployed by the Federal Emergency Management Agency until at least Monday evening — days after any victim had been found alive.

Fatigue and frustration are growing among rescue workers who are ending another long day of searching for those who perished in last week's Hill Country flood disaster. Some volunteers involved in the search are even resorting to on-site IV injections to get through the hottest day yet in the Guadalupe River basin,