Spring break for hundreds of thousands of Delta Air Lines passengers was disrupted by thunderstorms in Atlanta that led to an epic meltdown for the usually reliable airline. At the root of 4,000 canceled flights: telephone busy signals. An internal investigation into the April failure found the biggest problem was that Delta’s 13,000 pilots and 20,000 flight attendants calling in for new assignments couldn’t get through to the people...

Source: Wall Street Journal May 03, 2017 18:00 UTC