Severe winter weather impacted a lot of airlines this holiday season. But only one canceled more than 70% of its flights: Southwest. WSJ’s Alison Sider explains how the airline found itself at the center of one of the worst travel breakdowns in years. Further Reading: -How Southwest Airlines Melted Down  -Southwest Says It Maintains Normal Schedule as Airline Processes Bags, Refunds  -Southwest Airlines Cancellations Continue  Further Listening: -While Airlines Shrink, Southwest Goes Big  -How One Airline Sees the Future of Flying  Learn more about your ad choices. Visit megaphone.fm/adchoices