Search efforts continue for a fourth day as a girls' summer camp confirms 27 children and staff are dead, with 10 campers and one counsellor unaccounted for.

The heavy rain that turned a river in Texas into a raging wall of water was fueled by unique atmospheric conditions, according to meteorologists and climate scientists.

Flash floods swept through Texas over the Fourth of July weekend, leaving more than 90 people dead. Dozens remain missing.