Things are essentially back to normal three days after a computer upgrade issue resulted in over 5,000 flight cancellations worldwide, with the exception of Delta Air Lines. Atlanta-centered Delta canceled 1,500 flights on Friday, or about one-third of its scheduled itinerary. The flight-tracking firm FlightAware claims that's more than any other airline in the globe. Over the weekend, it grounded almost 3,000 more flights, and by early Monday, it had already canceled 700 more, or nearly 60% of all the flights that all airlines worldwide had canceled. Approximately one out of every six scheduled flights operated by Delta was canceled, compared to just 1% of flights operated by most other US carriers. Read more here.