Rare winter storm kills 21 in southern U.S.

The brutal cold has engulfed vast swaths of the United States, shuttering COVID-19 inoculation centers and hindering vaccine supplies. It is not expected to relent until the weekend.

Officials in Texas drew criticism as the state energy grid repeatedly failed, forcing rolling blackouts. Freezing weather stilled giant wind turbines that dot the West Texas landscape, making it impossible for energy companies to meet escalating demand.