A major technology outage grounded flights, hampered public transit systems and disrupted operations at banks and hospitals around the globe Friday in an incident a cybersecurity firm blamed on a faulty system update.

CrowdStrike, a U.S. firm that advertises being used by over half of Fortune 500 companies, said one of its recent content updates had a defect that impacted Microsoft’s Windows Operating System, adding the incident was “not a security incident or cyberattack.”

“The issue has been identified, isolated and a fix has been deployed,” said a statement from CrowdStrike. The company’s CEO, George Kurtz, apologized for the disruptions in an interview with NBC’s Today. Microsoft, meanwhile, said “the underlying cause has been fixed,” but residual impacts will affect some of its Microsoft 365 apps and services.

In the U.S., hundreds of flights were canceled Friday morning. American Airlines, Delta Air Lines and United Airlines were among those who grounded flights less than an hour after Microsoft said it resolved a cloud-services-related outage that impacted several low-cost carriers.

Public transit systems in the U.S. reported impacts. The Washington Metropolitan Area Transit Authority in Washington, D.C., said its “website and some of our internal systems are currently down,” but that trains and buses were running as scheduled. In New York City, the Metropolitan Transportation Authority also said its buses and trains were unaffected but that “some MTA customer information systems are temporarily offline due to a worldwide technical outage.”

Around the world, the outages disrupted London’s Stock Exchange, caused major train delays in the U.K., sent British broadcaster Sky News off air, forced medical facilities in Europe and the U.S. to cancel some services and caused disruptions at airports in Europe, Singapore, Hong Kong and India.

◾ Microsoft said all previously impacted Microsoft 365 apps and services have recovered, according to a post on X, formerly Twitter.

◾ The Federal Aviation Administration said in a statement on X that it’s “closely monitoring a technical issue impacting IT systems at U.S. airlines” and several airlines “have requested FAA assistance with ground stops until the issue is resolved.”

◾ Dubai International Airport said on X it is operating normally following “a global system outage that affected the check-in process for some airlines.” It added the affected airlines “promptly switched to an alternate system, allowing normal check-in operations to resume swiftly.”

-usatoday.com