Airlines and others rush to get back on track after global tech outage

Transport providers, businesses and governments on Saturday were working to get all their systems back online after disruptions following a widespread global technology outage.

The biggest continuing effect has been on air travel. Carriers canceled thousands of flights Friday and now have many of their planes and crews in the wrong locations, while airports face continued problems with check-ins and security.

By Saturday evening, the Chicago Department of Aviation reported 140 flights had been canceled and another 532 delayed in the preceding 24 hours at O’Hare Airport. Four flights had been canceled and 106 delayed at Midway Airport.

United Airlines posted on its website that “most” of its systems had been restored. The Chicago-based airline had listed 13 airports affected by the outage, including O’Hare.

“Our reliability is improving, although we will continue to see delays and cancellations,” United said, adding that it would waive change fees and fare differences for customers who chose to reschedule their trips.

Metra trains had a few cancellations and experienced minor delays Friday. The Chicago Transit Authority was unaffected by the outage.

Friday’s havoc began with a faulty update installed by CrowdStrike, a cybersecurity firm that provides software to numerous companies in multiple industries worldwide. Only its customers using Microsoft Windows, the most common computer operating system worldwide, were affected by the defective update.

The incident was not a result of a hack or any security issues, George Kurtz, CrowdStrike's chief executive, said in a social media post.

Microsoft estimates that nearly 8.5 million devices were affected by the outage, or less than 1% of all Windows machines, the company said.

“While the percentage was small, the broad economic and societal impacts reflect the use of CrowdStrike by enterprises that run many critical services,” Microsoft Vice President David Weston wrote in a blog post on the company's website.

Some hospitals and banks had temporary disturbances in their technology systems.

UChicago Medicine reported an overnight disconnection to hundreds of computer systems and servers that had been restored by Friday morning.

Banking services went largely uninterrupted Friday. BMO Harris and Fifth Third said their continuing issues mostly involved employee computer access and outside vendors, but customer operations were back to normal.

The outage also briefly hit arts organizations.

Notices previously posted to the Goodman Theatre’s and Steppenwolf Theatre’s websites telling customers that their ticketing systems would not be able to process electronic orders have been removed.