The issue is related to an update released for Windows computers by security firm CrowdStrike, the company said in a blog post. The company said the issue was identified and fixed at 6 a.m. Friday, but by then the effects had already spread worldwide.
The effects of the outage were a reminder of how much the global economy depends Computer systems are vulnerable to all sorts of problems, from sophisticated hacker attacks to botched software updates. But while the problems were widespread, there was also an element of randomness at play, depending on which companies in a given industry were using the faulty system.
CrowdStrike CEO George Kurtz said he was “deeply sorry” to everyone affected by the global outage during an appearance on NBC’s “Today” show Friday and vowed to “make sure every customer is fully restored.”
Many CrowdStrike systems are recovering and will be operational soon, Kurtz said, but “it could take some time for some systems that will not recover automatically.”
The company's problems follow a series of security incidents and service outages in recent years that have disrupted online services. Bruce Schneier, a security expert who teaches at Harvard Kennedy School, said the latest issue shows how fragile some aspects of the online world have become, as companies seek efficiency while sacrificing resilience.
“It’s one of hundreds of companies you’ve never heard of that are essential to the functioning of the Internet,” Schneier said. He compared the situation to a house built in such a way that nailing a picture to it puts it in danger of collapsing.
CrowdStrike's software is widely used around the world by companies looking to defend against hackers. The problems Friday affected only computers running Microsoft's Windows operating system, CrowdStrike said, leaving Apple computers and those running Linux untouched.
While Windows is the operating system on hundreds of millions of personal computers, it also runs on the behind-the-scenes computers that are critical to the operation of airlines, digital payment systems, emergency services call centers and other organizations.
Microsoft CEO Satya Nadella said in a post on X that his company was working with CrowdStrike and Windows users “to provide customers with technical advice and assistance to bring their systems back online safely.”
CrowdStrike noted in the blog post that the faulty file involved in the most widespread outages had a timestamp of 12:09 a.m. Eastern Time on Friday. An unrelated Microsoft outage on Thursday also caused problems.
The most visible consequences of the outage have been felt by airlines. U.S. budget carriers Frontier and Sun Country announced Friday morning that they were facing disruptions, and the problems have spread to major airlines and affected airlines abroad.
As of 6:30 p.m., more than 4,400 flights had been canceled worldwide. Of those, more than 2,700 were flights to, within, or from the United States, according to FlightAware.coman online flight tracking site. More than 40,000 flights have been delayed worldwide, including more than 10,000 to and from the United States.
United Airlines said the outage impacted several key systems: those used for customer check-in, calculating aircraft weights and operating call centers.
In the United States alone, the impact has been similar to what you might expect from a major snowstorm. And while airlines said they were back in business Friday morning, the aviation system's problems can take hours to fully resolve, with crews and planes stranded in the wrong cities.
John Cox and his wife spent more than a day at Reagan National Airport as they tried to catch a flight back to North Carolina.
On Thursday night, a technical glitch caused major airlines, including Delta, to delay flights and reroute passengers. Then their 10:17 a.m. flight to Charlotte on Friday was pushed back to noon Saturday. “It completely derailed our plans,” Cox said, slumped in a seat at the airport entrance.
“We’re going to end up spending a lot more money staying in Washington than we would have if we had stayed home,” Cox said, before leaning back in his chair and sighing. “There should be some compensation for the immense inconvenience that so many people are going through.”
By Friday morning, it had become clear that the effects were reaching across a wide range of industries and affecting government agencies.
The effects on medical providers have spread from the United States to Israel, with doctors losing access to electronic medical records and some hospitals postponing elective procedures.
Mass General Brigham, a nonprofit organization that operates one of the largest hospital systems in Massachusetts, said on its website website The organization announced Friday that it was canceling all “non-urgent visits” to its hospitals and clinics. The organization said its emergency departments remained open and were providing care for urgent appointments and procedures.
Alison Baulos said her father, Gary Baulos, was scheduled to have heart surgery Friday at Baptist Health in Paducah, Ky., but he received a call at 3:30 a.m. that the procedure was canceled because of the outage.
Her father, a 73-year-old former Navy Seabee and AT&T technician, had just been diagnosed with eight blockages and an aneurysm, she said, and spent Thursday night in a hotel near the hospital.
“The doctor said he couldn’t be too active, he couldn’t raise his hands above his head,” Alison Baulos said. She added that her father was taking the situation lightly. His reaction to the cancellation, she said, was, “Well, since we’re already here, I guess we can go to IHOP for breakfast.”
Danielle Carzell, a 35-year-old Atlanta resident, was scheduled to have hip replacement surgery Friday, a procedure she had been looking forward to for months. Born with a genetic disorder (her hips are “like mismatched puzzle pieces”), she is in constant pain and hoped the surgery would provide relief. But after waiting hours at Emory St. Joseph Hospital, she was told the surgery would have to be rescheduled because of the outage.
“I have no idea when I’m going to be able to have surgery,” she said. “I have a 5-year-old that I just want to play with, and this breakdown is ruining everything.”
Even in an industry that has suffered major blows this year — including hacks of claims processors Changing Health Care and the health system Ascension — Experts were surprised by the scale of the impacts on Friday.
“I was shocked to see that ripple effect,” said Chris Cummiskey, a cybersecurity expert and former Department of Homeland Security official. While CrowdStrike is often considered the gold standard for cyber protection, he said the event may require an overhaul of the company’s internal practices.
“We don't want to push a single button and cause a global collapse like that,” Cummiskey said.
Television stations in several countries were grounded. In Australia, ABC News was unable to broadcast its regular evening newscast, so it aired a special report on the disruption at Sydney airports.
Some emergency services also reported problems. Alaska State Police reported that as of 9 p.m. local time Thursday, 911 call centers across the state were not functioning properly. Service was restored around 4 a.m. Friday as dispatch centers switched to analog phone systems or partnered with dispatch centers that had not been affected, according to the Alaska Department of Public Safety.
Federal officials rushed to assess the situation and provide assistance. Anne Neuberger, a security and technology adviser to the President Bidensaid his day began with a call with the White House Situation Room at 4 a.m. as the government sought to determine the effects on its own systems and critical parts of the economy.
“This highlights how our economies and our national security are now digital and interconnected in fundamental ways,” Neuberger said, speaking on a panel at the Aspen Security Forum in Colorado.
A White House official said Biden himself had been briefed on the outage and that the administration was in contact with CrowdStrike and affected entities. The White House will receive “sector-by-sector updates throughout the day and stands ready to provide assistance as needed,” the official added.
Transportation Secretary Pete Buttigieg said in an interview on CNBC Friday that he expected airlines, ports and freight companies to be largely back on their feet by Friday. But he added that the episode should prompt reflection on the country’s vulnerability to even seemingly minor technical problems.
“We’re in a new era in terms of these risks,” Buttigieg said. “I think there’s going to be a huge evaluation after the fact, once the dust settles and things get back to normal.”
Hannah Ziegler, Jeff Stein, Aaron Gregg, Adela Suliman and Julian Mark contributed to this report.
