About 150 flights canceled after Delta grounds U.S. flights

Delta Air Lines canceled 150 flights Sunday after grounding its U.S. flights due to an automation issue, the company said in a statement. And the company expects more cancellations.

Delta said in a statement around 11:45 p.m. ET that airline's IT systems "returned to normal" the ground stop was lifted. The cancellations and delays left thousands of airline travelers in limbo across the country.

“I want to apologize to all of our customers who have been impacted by this frustrating situation,” Delta CEO Ed Bastian said. “This type of disruption is not acceptable to the Delta family who prides itself on reliability and customer service."

Ask the Captain: Automation in aviation

The Delta systems didn't show the latest total of cancellations late Sunday night, including delta.com, the Fly Delta App, airport information screens or through our Reservations agents, according to the statement. Some customers experienced delays upon landing, particularly at Delta’s hub airports.

The grounding was reported earlier Sunday in a statement by the Federal Aviation Administration's Air Traffic Control System Center. International flights were exempt.

Reports on social media Sunday showed flight disruptions at airports in Atlanta, New York City, Houston, Tucson, Austin, and other U.S. cities.

Exactly a week earlier, United Airlines grounded its domestic flights due to a computer outage. In that outage, as in this one, international flights were not affected.

U.S. officials last Sunday said the Aircraft Communications Addressing and Reporting System, or ACARS, was having issues with low bandwidth.

Delta offered a waiver for flights scheduled Sunday and Monday, which can be rebooked by Feb. 3.

Delta won't accept unaccompanied minors will not be accepted for flights through noon ET, Monday, according to the statement.

Follow Greg Toppo on Twitter: @gtoppo; follow Steph Solis on Twitter: @stephmsolis