Judy Woodruff:

This has been a day for the record books. It was colder in parts of the American Midwest today than it was at the South Pole. The arctic assault claimed at least seven lives and disrupted planes, trains, automobiles, and just about everything else.

Visions of a frozen world. A wall of steam rose off Lake Michigan in Chicago this morning. Rivers in the Windy City and Detroit froze to sheets of ice. And in Milwaukee, subzero readouts at a landmark clock tower were topped by flags standing at attention in winds that sent chills down to minus-43.

Human skin can freeze within 15 minutes in minus-25, as Michigan's governor warned today.