Started overnight. Evidently computer failure is systemwide. Flights that were already in the air are being allowed to continue to their destinations, but no flights are being allowed to take off. https://gma.yahoo.com/delta-airlines-grounds-flights-due-global-computer-outage-094507616--abc-news-topstories.html# First Southwest. Now Delta. Wonder if this is a series of hacking incidents??? AA and United next?