 They helped build out a timeline for what Crooks was doing in the days leading up to the attempted assassination of Trump, although investigators say they still do not have an answer as to why he did it. Ryan Lucas, NPR News, Washington. 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.