There was already a brief ground stop Friday morning due to wind at SFO, delaying inbound flights from taking off, but now the FAA has ordered a sudden, nationwide ground stop due to some massive communications failure.In only the second instance of a nationwide ground stop since 9/11, the Federal A viation Administration (FAA) ordered all flights to remain on the ground across the US Friday afternoon. As CNN reports, the ground stop was ordered around 1:30 pm, and early indications suggest that this was not due to any sort of cyberattack.Secretary of Transportation Sean Duffy posted to social media that the order came "following a communication issue impacting all Air Route Traffic Control Centers."The ground stop was indefinite, and as the Chronicle reports, air traffic controllers at SFO were telling pilots on the tarmac that departures were going to be halted until 8 pm, unless those instructions change.According to CNN, flights in the air approaching Chicago were told that the situation was "ATC Zero," meaning zero air traffic control.In audio heard by CNN, a controller told pilots, "We lost all of the frequencies and all of the automation for the handoff and strips and stuff."Certainly sounds like a cyberattack!The last similar ground stop occurred in January 2023 when a pilot notification system went down, and prior to that, there had not been a nationwide ground stop since September 11, 2001.Homeland Security Secretary Markwayne Mullin gave a statement, per the New York Times, saying they weren't ruling out an attack of some kind, but, he said, "There was no indication as of yet that this was a nefarious attack against us,” and, “It’s just a telecommunication outage as of right now."An anonymous congressional official told the Times that both the White House National Security Council and the Pentagon had told their office that they did not yet know the cause of the outage.The FAA's Airspace System Status site still has not updated with any notice of the nationwide ground stop, and it is showing an average delay at SFO of 138 minutes "due to wind."This is a developing story. ...read more read less