A complete power outage at the nation’s busiest airport, the Hartsfield-Jackson Atlanta International Airport, grounded flights Sunday afternoon, threatening to cause a holiday travel nightmare for fliers across the country just over a week before Christmas. Airport officials said in a news release the power outage has forced the Federal Aviation Administration to suspend outgoing flights and implement a "ground stop" for incoming flights, which "means that flights headed to Atlanta are held on the ground at their departure airport." International flights will be diverted to land at other airports, U.S. Customs and Border Protection tweeted. Atlanta Airport tweeted that...