The National Weather Service began sending flash flood warnings that should have triggered cellphone alerts a little after 1 a.m., while local officials began posting on Facebook about four hours later.

Flash flooding in Texas Hill Country has triggered one of the largest rescue operations in the state’s history

The downpours that swept away a children's summer camp and wreaked deadly havoc on huge areas of Texas caught holidaymakers by surprise. As the death toll passes 90 people, questions are being raised about whether adequate flood warnings were provided and why people weren't evacuated ahead of the deluge.

Janie Hunt was the great-granddaughter of the late American oil baron William Herbet Hunt and a cousin of Clark Hunt, the current owner of the Kansas

"Camp Mystic is grieving the loss of 27 campers and counselors following the catastrophic flooding on the Guadalupe River," the camp said in a statement.