Rivers rose and flooding worsened Sunday across the sodden U.S. South and Midwest, threatening communities already badly damaged by days of heavy rain and wind that killed at least 18 people.

A storm system has resulted in at least 16 deaths in the South and Midwest, with overnight tornado and flash flood warnings.

At least 16 people have been killed in a wide swath of violent storms, flooding and tornadoes that hit the South and Midwest.

Round after round of heavy rains have pounded the central U.S., leading to rapidly rising waterways and prompting a series of flash flood emergencies Friday night in Missouri, Texas and Arkansas.