HuffPost's live-updates article reports the Federal Aviation Administration's nationwide ground stop on Friday, citing "extraordinary circumstances" from communications issues at regional air traffic control centers, delayed nearly 10,000 flights and cancelled 5,000 before being lifted shortly after 8 p.m. EST. Homeland Security Secretary Markwayne Mullin scolded a reporter for asking whether "AI" caused it rather than President Trump's preferred "SI," while officials including Mullin and Sean Duffy said the stoppage was not a cyberattack or AI and was instead an overloaded legacy communications system.