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.

Survivors have described the floods along the Guadalupe River as a “pitch black wall of death” and said they received no emergency warnings.

Six counties reported deaths from multiple severe flood events since Friday, July 4. Also, Kerrville officials reported that a privately owned drone collided with a helicopter conducting search and rescue operations.