"We're just kind of on damage control right now," Tieu said. "Lots of traffic direction."

Tieu said he was aware of one person on the West Side who was treated at the scene for a minor injury.

Debris lined the streets in several neighborhoods, from whole trees to branches to the contents of garbage and recycling bins tossed around by the high winds.

The National Weather Service's McMahon said potential tornadoes also were reported in Green County west of New Glarus and in Iowa County south of Mineral Point.

Meanwhile in Grant County, UW-Platteville announced that it would be closed on Tuesday due to storm damage. All classes and activities are canceled, with only essential employees asked to report to work.

In the tiny northeast Nebraska town of Pilger, the National Weather Service said two twisters touched down within roughly a mile of each other. Emergency crews and residents spent the evening sifting through demolished homes and businesses in the community of about 350, roughly 100 miles northwest of Omaha. At least 19 people were injured in addition to the one boy who was killed.