The Federal Aviation Administration ordered all American Airlines flights grounded just before 7 a.m. Tuesday after the airline reported a technical problem affecting its entire system.

“A vendor technology issue briefly affected flights this morning,” an American Airlines spokesperson said in a statement to the Washington Examiner. “That issue has been resolved and flights have resumed. We sincerely apologize to our customers for the inconvenience this morning. It’s all hands on deck as our team is working diligently to get customers where they need to go as quickly as possible.”

The grounding occurred as millions of travelers plan to fly out to see families and loved ones for the Christmas holiday. The Transportation Security Administration expects to screen 40 million passengers through the holiday and through Jan. 2, 2025.

As holiday flights are typically booked up with all seats taken, any delays in flights can lead to cancellations that take days to clear up.

American Airlines’s temporary grounding comes two years after Southwest Airlines left 2 million travelers stranded. Southwest had to pay a $35 million fine as part of a $140 million settlement due to a federal investigation into the 2022 Christmas strandings.

Earlier this year, Delta Airlines also suffered a four-day meltdown following the CrowdStrike worldwide technology outage in July, stranding tens of thousands of passengers.