A “defect” in a software update from the cybersecurity firm CrowdStrike was apparently the cause of the outage.
Shortly before 6 a.m. EDT on Friday, CrowdStrike said the issue had been “identified, isolated and a fix has been deployed.”
“The underlying cause has been fixed, however, residual impact is continuing to affect some Microsoft 365 apps and services,” Microsoft said in a post on the social platform X. “We’re conducting additional mitigations to provide relief.”
Businesses around the globe were impacted by the outage.
More than 3,000 flights have been cancelled another 27,000 have been delayed, according to the flight tracking site FlightAware.
The issue caused major U.S. carriers American, Delta and United Airlines to halt flights early Friday morning, although all three had resumed operations by mid-morning.
The outage also disrupted hospital operations. The Boston-based health system Mass General Brigham canceled all non-urgent visits at its hospitals and clinics, and the National Health Service (NHS) in England said the outage led to disruptions in “the majority of GP practices.”
The British news channel Sky News also said it was unable to broadcast live Friday morning.
Across the English Channel in Paris, the Olympic organizing committee said the outage has “limited” impacts one week before the opening ceremony.
But emergency services across the United States, including Alaska state troopers and the Phoenix Policy Department, went down due to the outage. Systems were both back up and running early Friday, according to each group.
The Hill’s Julia Shapero and Rebecca Klar have more here.
