The Federal Aviation Administration's decision to ground all flights nationwide Friday threw the sports world into chaos, leaving NBA, NHL and college teams stranded as they tried to reach their destinations, and NFL teams were left to wonder whether the issue would be resolved in time to travel to their games this weekend.

The FAA issued a notice that said the ground stop was “due to extraordinary circumstances and for reasons of safety."

Transportation Secretary Sean Duffy later said there was a communications issue affecting the 22 regional air traffic control centers that direct planes en route between airports nationwide, and that FAA technicians were investigating.

“There’s no reason to be concerned about your loved ones if they’re flying,” Secretary of Homeland Security Markwayne Mullin said.

Most college football teams playing Saturday travel the day before their game, and the stoppage left many schools — including No. 2 Utah, eighth-ranked Texas and No. 9 Tennessee — at a standstill as they departed for road games. The Utes play at No. 22 Arizona, the Longhorns visit No. 24 LSU and the Vols are traveling to Texas A&M in three of the bigger games of the weekend.

“The Southeastern Conference is aware of the FAA's nationwide ground stop and the potential impact on team travel for this weekend's competitions,” the league said in a statement. “We are in close communication with our member institutions to assess potential disruptions and coordinate appropriate responses. The safety and well-being of student-athletes, coaches and team personnel remain our highest priority.”

The Longhorns posted on social media a short video of them boarding their plane before the stoppage began. If they ended up taking a bus to Baton Rouge, Louisiana, the trip for the 6:30 p.m. CT kickoff against the Tigers on Saturday would take about seven hours.

"We are grounded and waiting to see when we can leave,” a Texas team spokesman said.

Other schools affected by the stoppage included No. 19 Ole Miss, Baylor, Washington, Kansas State and Minnesota.

Asked whether Kansas State had an alternative plan for its trip to Baylor, a school spokesman replied: “Nothing at this point.”

San Jose State’s football team had boarded a plane and was on the runway for its trip to Air Force for a game Saturday when the plane turned around and went back to the gate. The team returned to campus and was waiting to see what happens.

It also was unclear whether referees, who typically fly to their assignments the day before games, would make it on time.

Several teams were able to take off before the stoppage went into effect, including all those traveling in the Atlantic Coast Conference; Missouri, which was flying to top-ranked Georgia; Duke, which was visiting fifth-ranked Miami; and No. 10 Texas Tech, which posted on social media images of its arrival for a game at Oklahoma State.

Meanwhile, the Nets were among five NBA teams scheduled to fly Friday for games on Saturday. They had just boarded the team plane in New Orleans after playing the Pelicans earlier this week when their flight to Memphis was halted in place.

The Pistons flew earlier in the day to Miami. The Cavaliers, Bulls and Grizzlies play Friday night and were due to fly afterward.

There are 14 scheduled games in the NHL on Saturday. The Panthers were among the majority that made it to their destinations before the stoppage began, but the Sharks were left waiting in San Jose to see whether they would be able to travel to Utah.

The FAA did not provide a timeline for restarting flights, leaving sporting events taking place beyond Saturday in limbo. That includes most of the Week 10 schedule in the NFL along with numerous college sporting events.

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AP Sports Writers Jim Vertuno, Aaron Beard and Tim Reynolds contributed to this report.

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