 Flights have resumed at several U.S. airlines after a massive communications outage that wreaked havoc on companies around the world. More from NPR's Joel Rose. Delta, American, and United Airlines were hit hard by the IT outage. All three airlines say at least some flight departures have now resumed. But delays and cancellations are likely to ripple across the U.S. airspace for the rest of the day and even into the weekend as airlines struggle to get equipment and personnel in the right position.