On February 14, the expected impacts from the storm resulted in over 170 million Americans being placed under various winter weather alerts across the United States, which saw the largest portion of the country covered by winter weather alerts in 15 years. Over 120 million of those people were placed under winter storm warnings or ice storm warnings by the National Weather Service. The winter storm caused power grids to fail across the U.S., causing blackouts for over 5.2 million homes and businesses, the vast majority of which were in the state of Texas, which became one of the largest blackout events in modern U.S. history, the largest one since the Northeast blackout of 2003. The storm left at least 164 people dead across the United States, with 151 of them in Texas. The initial death toll had been estimated at 70 before it was later revised upward, after more information was collected. The system was estimated by NOAA to have cost $20.4 billion in damage, making it the costliest winter storm in U.S. history.