More than two-thirds of the U.S. population was under an extreme weather alert on Friday as a deep freeze enveloped much of the country ahead of the holiday weekend, thwarting travel plans, knocking out power to homes and businesses and causing at least three deaths. With a column of bitter cold that stretched from Texas to Montana starting to march eastward, more than 240 million people were under weather advisories on Friday, the National Weather Service said. Hard-freeze warnings were posted in parts of the Southern states of Louisiana, Alabama, Florida and Georgia.
