A U.S. Customs and Border Protection (CBP) computer system outage on 2 January 2017 caused long airport delays to post-New Year’s travelers in a multi-site incident officials maintained was not “malicious” in nature. 

The outage began at approximately 5:00 PM Eastern Standard Time and lasted for about four hours. In a statement provided to CBS News, CBP said airport security agents used “alternative procedures” to clear travelers during the hours-long systems glitch:

“CBP took immediate action to address the issue and CBP officers continued to process international travelers using alternative procedures at airports experiencing the disruption,” CBP spokesperson said in a statement. “Travelers at some ports of entry experienced longer than usual wait times as CBP officers processed travelers as quickly as possible while maintaining the highest levels of security.”

It is unclear how widespread the outage was, but issues were reported in Miami, Fort Lauderdale, Atlanta and Washington Dulles International Airport. The outages began around 5 p.m. EST and ended around 9 p.m. EST, CBP said.

As is typically the case with widespread air travel disruptions, social media were flooded with images shared by frustrated flyers, many of whom reached out to the news media for assistance:

CBP and multiple airports also used Twitter to disseminate information to both affected travelers and the news media during and after the outage:

CBP spokesman Daniel Hetlage reiterated that screening of entrants continued while systems were down, adding that the outage appeared to not be the result of any digital attack of any sort:

During the technology disruption, CBP had access to national security-related databases and all travelers were screened according to security standards. At this time, there is no indication the service disruption was malicious in nature.

Travelers caught up in the outage’s effects claimed that neither airlines nor airports explained the delays during the hours-long outage. Utah resident Jennifer Powers-Johnson flew into Salt Lake City International Airport from London during the systems failure and told CNN that

Delta had us all line up after we landed and it took a while before customs was even able to find us a place where we could wait because the airport is so small. I would not have had any idea of what was going on if my cousin did not text me.

Additional passengers complained that the situation was confusing on the ground, asserting that travelers were insufficiently apprised of the ongoing computer problems:

College student Chinedu Elendu was returning with his brother and sister from a family vacation in Nigeria when the outage held him up for about an hour and a half at San Francisco International Airport.

They had just finished two legs of their journey: a 6.5-hour flight from Nigeria to Frankfurt, Germany, followed by an 11.5-hour flight to San Francisco, he said.

“When we got to the place in customs where you scan your passport, my brother and sister scanned theirs and got through fine. Mine did not scan and I had to get in a different line. That was the line that took so long,” Elendu said.

No announcements were made at the airport explaining the delay, he said. He overheard people talking about a nationwide computer problem affecting people with all kinds of passports.

U.S. Travel Association president and CEO Roger Dow blamed rapidly aging processing systems across points of entry for the failure, positing that system strain could worsen in the coming weeks and years:

What happened at Customs airport checkpoints yesterday is disturbing, but unfortunately it is not surprising … Technology at these facilities is too outdated to cope with existing travel volume, let alone the increased traffic we hope and expect to see at our gateway airports in years to come.

According to NBC News, affected airports included “Miami International, Fort Lauderdale/Hollywood (Florida) International, Hartsfield-Jackson Atlanta International, John F. Kennedy International (New York), Logan International (Boston) and Los Angeles International.” NBC linked to an October 2015 report of a similar failure, during which CBP stated there was no indication the “service disruption was malicious in nature” and added that “alternative procedures” were used for screening.