Southwest Airlines planes were grounded nationwide Tuesday for what the carrier called an intermittent technology issue.
AP reports the stoppage has caused more than 1,500 flight delays just four months after the airline suffered a meltdown during the Christmas travel rush.
Southwest and the Federal Aviation Administration (FAA) predicted by late morning on the East Coast the pause may be lifted but no guarantees were offered to travelers stranded in crowded terminals across the country.
The Dallas airline said in a prepared statement seen by AP:
Southwest has resumed operations after temporarily pausing flight activity this morning to work through data connection issues resulting from a firewall failure.
Early this morning, a vendor-supplied firewall went down and connection to some operational data was unexpectedly lost.
By late morning on the East Coast, Southwest accounted for well over half of all delays nationwide, but the airline had canceled fewer than a dozen flights, according to FlightAware.
In earlier tweets replying to frustrated travelers who said they were stranded on airport runways, Southwest said it “had to implement a ground stop as a result of intermittent issues that were experienced.”
About one in five Southwest flights — nearly 800 — are still delayed.
As Breitbart News reported in December, Southwest canceled nearly 17,000 flights over the Christmas holiday due to bad weather and its crew-scheduling system becoming overwhelmed.
Those cancellations cost the airline more than $1 billion and are being investigated by the Transportation Department.