TechCrunch reports that Transportation Secretary Sean Duffy blamed a nationwide ground stop — only the third of the 21st century — on a seemingly routine fiber optic upgrade by FAA contractor L3Harris, saying a router overloaded a critical communication system, with the agency investigating whether the cause was user, installer, or equipment error. More than 8,200 flights were canceled Friday per Cirium, at least 3,000 more Saturday, and Duffy said the timing of such work will be reevaluated while pressing Congress for more funding.