Transcript for Computer Crash at Airports Snags Travel
Next tonight, to a computer crash, leading to long lines at several airports here in the U.S. That crash involving the terror watch list. Tens of thousands of passengers affect affected. This extended to Washington, new York, Boston and beyond. Here's ABC's David Kerley tonight. Reporter: Part of the critical security system that checks those coming into the country slowed to a crawl, leaving thousands of travelers in line. They just said there was a nationwide computer glitch. Reporter: More than 20,000 passengers affected at us can on thes. This is crazy. Reporter: The system problem affecting international airports. Was this a security threat? I don't think so. That they do have redundant systems in place to ensure that bad people can't come into the country. Reporter: The problem? Those redundant systems are slower, which is why, for those thousands of travelers, it was a wait. We needed to fill out some forms, old school style and, so I filled out the form. Reporter: The customs and border protection problem lasted for 90 minutes. It took longer for the lines to disappear. Each day, 300,000 passengers pass through the country's airports. Customs and border protections tells us there is no indication there was a security breach or a hack in their computer system. And the computer slowdown did not jeopardize security. David Kerley, ABC news, Washington. David, thank you.
This transcript has been automatically generated and may not be 100% accurate.