FAA ground stop live updates: Duffy blames 'overloaded' routers; thousands of flights canceled

Nearly 5,000 flights have been canceled nationwide Friday, according to FlightAware.

There are nearly 800 cancellations for Saturday.

The Big 12 Conference said Friday it is "evaluating any potential changes to Saturday's football schedule" due to the national ground stop.

"The Conference will continue to monitor the travel disruptions alongside its member institutions and provide updates for Saturday's games," the college athletic conference said in a statement.

A small number of flights are taking off over the ocean and in Alaska and Hawaii.

Alaska and Hawaiian Airlines said in a statement that flights within Hawaii and from the West Coast to Hawaii can continue. International flights from Hawaii are also cleared. 

Hawaii's Department of Transportation said that flights between Anchorage to Oakland and Hawaii can fly.

San Francisco International Airport said that Pacific-bound flights are cleared to depart from the airport, including to destinations in Alaska and Hawaii.

Ontario Airport in California said that flights heading west over the ocean are allowed to take off from the airport at this time. 

Boston Logan said in a post that the FAA is permitting some transatlantic flights to depart.

-ABC News' Bonnie McClean

Transportation Secretary Sean Duffy said in an X post Friday that the ground stop was "due a communication issue impacting all Air Route Traffic Control Centers."

Air Route Traffic Control Centers are responsible for communication for all flights above 18,000 feet. There are 22 of these towers located in some of the nation's major hubs including New York, Los Angeles and Atlanta.