>> that's probably the one thing that did work yesterday. right. we're talking about united airlines. travel nightmare for thousands of people across the country. united airlines apologizing, though, after all of their flights grounded for about two hours. the ripple effect dragged on and on. yes, another computer glitch we're told here. more now from abc's marcy gonzalez. >> reporter: at airports across the country, blank screens and long lines. >> we can barely get in the door because the lines were so long. >> reporter: a travel mess starting at around 10:00 eastern with every united airlines flight nationwide that hadn't taken off suddenly grounded. >> here sends us back to the computer thing which says it can't help us. >> reporter: the airline blaming it on a computer glitch that caused a connectivity issue keeping united from being able to communicate with its planes on the ground or check passenger in. >> it's unbelievable how much we rely on the computers. when we arrived here, this was wall to wall people because there was no way to process.