Freeze alerts issued overnight across a swath of the South, from Texas to Florida, where 15 million Americans shivered under their blankets. Of the 51 cold-related deaths since Jan. 12, 17 happened in Tennessee, nine in Oregon, six in Illinois, five in Washington state and Mississippi, three in New York state, two in Louisiana and one each in Arkansas, Wisconsin, Wyoming and New Hampshire. All state offices in Tennessee were closed Friday because of the dangerous winter weather.