Southwest Airlines temporarily grounds all flights over technology problem

Southwest Airlines is resuming flights after grounding all planes in the U.S. Tuesday morning over a technology issue.

In a statement at 11 a.m. Eastern time, the discount carrier said it “resumed operations” after requesting a ground stop Tuesday 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. Southwest teams worked quickly to minimize flight disruptions,” the carrier said in a statement.

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 1 in 5 Southwest flights — nearly 800 — are still delayed, according to airline tracker FlightAware.

This is a developing story. CBS News’ Kathryn Krupnik and Kris Van Cleave contributed reporting.