Updated at 7:15 a.m. CT: Passengers are reporting that American Airlines flights across the country are returning to the skies after a temporary system outage grounded planes. Passengers confirm that they are being boarded back into planes in Dallas, Texas, St. Louis, Missouri, and Charlotte, North Carolina.

The Associated Press reported that American flights were cleared to fly by federal regulators about one hour after a national ground stop order was issued by the Federal Aviation Administration.

There were 1,447 delays for flights entering or leaving the U.S. early in the day, with 28 cancellations. Snow was falling early in New York and Dallas-Fort Worth International, which is American Airlines’ main hub, was getting hit with rain, the AP reported.

Dallas-Fort Worth had the most delays, followed by Charlotte, North Carolina, Washington, New York, Chicago and Miami, the AP said.

American said in an email that the problem Tuesday morning was caused by a vendor technology issue that “impacted systems needed to release flights.”

Previous report:

American Airlines passengers faced a very Grinch-like morning after all flights from the airline were temporarily grounded. The Texas-based company blamed an IT outage that prevented planes from taking off on Christmas Eve.

People on Reddit reported boarding flights in multiple cities, including Austin, Texas, St. Louis, Missouri, Dallas, Texas, and Miami, Florida, only to be told to deplane, with American Airlines providing no information about how long the outage would last.

The outage only impacted American Air airlines flights. Popular flight tracking apps like FlightAware.com were not consistently reporting outages, making it advisable for travelers to check with friends and family on their flight status before heading to the airport.

Southwest Airlines, another Texas-based company, had a disastrous Christmas in 2022, with more than 25% of its flights canceled due to a system outage and winter storm.

The Associated Press reported that Southwest was ordered to pay a $35 million fine as part of a $140 million settlement to resolve a federal investigation into the debacle.