Holiday storms sweep through U.S.

At least three people were killed as tornadoes and severe weather struck the southern U.S., as the bad weather migrated toward the Northeast and threatened to cause further disruptions on one of the heaviest travel days of the year. More than 600 flights nationwide were canceled and more than 5,000 delayed on Tuesday, according to the flight tracker FlightStats.com. Many were out of the Dallas-Fort Worth airport. As of shortly after 7:30 a.m. Wednesday, over 450 flights had been cancelled and more than 500 delayed across the U.S.