Tornado hits Sioux Falls, Avera

A storm that tore across Sioux Falls overnight was so treacherous, even weather forecasters had to pause their work and hunker down. Now city officials are investigating why not all of the city’s outdoor warning sirens sounded like they should have.

The severe weather that struck South Dakota’s largest city spawned at least one tornado, the National Weather Service said. “Obviously we had widespread damage throughout the entire city,” said Todd Heitkamp of the weather service’s Sioux Falls office.

“Most of that damage was a result of probably 100-mph-plus winds. And some of the damage was a little bit more intense, and we’re suspecting that was a result of some brief, spin-up tornadoes.” Eight people at the Avera Behavioral Health Center were injured in the storm, Sioux Falls Mayor Paul TenHaken told CNN.

The hospital suffered storm damage and was evacuated. Across the city, at least 37 structures either collapsed or had integrity issues, the fire department said.