A historic winter storm has killed at least 21 people, left millions of Texans without power and spun killer tornadoes into the U.S. Southeast on Tuesday. 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. At least 21 people have died in Texas, Louisiana, Kentucky and Missouri including four killed in a house fire in Sugar Land, Texas, where the power was out, according to police and local media. President Joe Biden assured the governors of hard-hit states that the federal government stands ready to offer any emergency resources needed, the White House said in a statement. In the Southeast, a low-pressure system that developed along the Arctic front created fuel for storms that unleashed at least four tornadoes, said meteorologist Jeremy Grams of the weather service’s Storm Prediction Center in Norman, Oklahoma. One ripped through the Florida Panhandle and two through southwestern Georgia on Monday.