Department of Homeland Security Secretary Markwayne Mullin said that the ground stop was not prompted by a security threat. “This is a telecommunications outage out of the FAA. Out of an abundance of caution, we have grounded all of the flights,” Mullin said. “There’s no indication as of yet that this is a nefarious attack against us.”
Mullin had said the FAA would handle incoming international flights on a case-by-case basis.
This was only the third nationwide ground stop issued by the FAA. The first, and most memorable, came during the attacks of September 11, 2001, when the FAA stopped all civilian departures nationwide and subsequently ordered all airborne aircraft
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