NEW YORK (CBSNewYork) -- All United Airlines domestic flights were grounded for about two hours Sunday night due to "an IT issue."
Sources told CBS News' Kris Van Cleave the airline's Aircraft Communications Addressing and Reporting System (ACARS) went down. The system records and transmits information that pilots need to know in order to safely take off.
Karen Johnson, of Windsor, was traveling to Denver for job training.
"We were supposed to leave at 6:20, got a notice from the captain that all United flights' computers were down and all United flights were grounded," she told CBS2's Raegan Medgie at LaGuardia Airport.
Johnson said passengers were told to stay on the plane, then two hours later, were told to get off.
"Now I don't know. I'm just going to go smoke a cigarette, relax, hit the bar and hopefully get back on the plane," she said.
"The flight attendants seemed a little frustrated, passengers seemed a little frustrated, everybody just wants to go him I guess," said another passenger, John Bryan, of Houston.
About two hours later, United announced it had lifted the ground stop.
International flights were not impacted by the outage, according to the Federal Aviation Administration.
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