More than 20 people are dead and about a thousand have been displaced by the storms and accompanying floods. Of the thousands of affected homes, 256 are completely destroyed, according to preliminary surveys by the American Red Cross.

In Wisconsin, a woman and her child died at a bus stop when lightning struck a utility pole and knocked a live wire into the flooded streets. A passerby who tried to save them was also electrocuted.

"A lot of officers were affected because they couldn't jump in there and help, because the wires were still live," Madison police spokesperson Mike Hanson told the Associated Press. "There are some heavy hearts."

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