A wave of IT outages swept across the globe Friday morning, causing thousands of flight cancellations and stalling internal and external systems across a variety of industries including hospitals, banks, stock exchanges and other institutions, as some Microsoft-based computers ceased to work.
CrowdStrike -- an American cybersecurity technology firm that provides cloud workload protection, threat intelligence and cyberattack response services -- said the outage is not a due to a cyber attack; it was caused by a software issue that has been identified and a fix had been deployed.
Some systems can be fixed and back up and running immediately -- but for others it "could be hours, could be a bit longer" before everything is back up and running, CrowdStrike CEO George Kurtz told CNBC in an on-air interview. For some customers, it will take more than rebooting systems to work through fixes.
"CrowdStrike is actively working with customers impacted by a defect found in a single content update for Windows hosts. Mac and Linux hosts are not impacted," Kurtz said earlier Friday.
In a letter to customers and partners, Kurtz apologized for the outage which he said was "caused by a defect found in a Falcon content update for Windows hosts."
"We know that adversaries and bad actors will try to exploit events like this. I encourage everyone to remain vigilant and ensure that you’re engaging with official CrowdStrike representatives. Our blog and technical support will continue to be the official channels for the latest updates," Kurtz said.
"As this incident is resolved, you have my commitment to provide full transparency on how this occurred and the steps we’re taking to prevent anything like this from happening again," Kurtz said.
Several states are experiencing a disruption in emergency communication services, according to a Department of Homeland Security Cybersecurity and Infrastructure Security Agency memo obtained by ABC News.
The mayor of Portland has signed an Emergency Declaration which has impacted city servers and employee computers, including impacts to VPN connection and single sign-on cloud services.
In Phoenix, Arizona, the outage impacted the Phoenix Police Department’s computerized 911 dispatch center, but the 911 center remained operational. City IT is working diligently to find a workaround until the outage has been resolved.
In Alaska, many 911 and non-emergency call centers were not functioning correctly across the state, according to Alaska State Troopers. Some 911 services were down overnight in New Hampshire as well, but they have since been restored.
New York City officials said that emergency services are fully operational and have not been impacted by the outages.
The Superior Court of Los Angeles County is also experiencing significant system-wide connectivity issues impacting the court's ability to conduct businesses. Remote hearings scheduled for Friday have been rescheduled and parties will be notified of the new date.
Some computers have been affected at Department of Justice in the outage, though there was no indication that it was affecting law enforcement activities in the field, a source told ABC News. A notice issued by the DOJ Office of the Chief information officer said the issue is "significant" and there is no restoration time.
The DOJ alerted users that they are among the businesses and government users worldwide affected and that the DOJ Office of the Chief Information Officer has actively been troubleshooting possible workarounds with Component CIOs and technical teams.
Law enforcement has been notified that there are already online actors and hackers who are attempting to infiltrate corporate and government IT networks by distributing emails with malware disguised as bogus software fixes for the CrowdStrike problem, a non-government source working on the problem told ABC News.
The U.S. Department of Health and Human Services has also put out an alert to hospitals and law enforcement reporting that “multiple government agencies” have been affected, including the secretary’s operations center - even as the problem is starting to roll back.
MORE: CrowdStrike stock price plummets amid worldwide IT outageSome hospitals around the country have also been affected in the IT outage. Mass General Brigham in Boston canceled all elective surgeries on Friday and Cincinnati Children's Hospital Medical Center in Avondale, Ohio, also reported some disruptions.
The Catholic Health system also said it is facing outages that are causing delays, but its hospitals and medical practices remain open.
The D.C. Metro system was also impacted, telling ABC News some of its internal systems were down and IT teams are working to resolve the issue.
New York City's mass transit system, the largest in the U.S., says that bus and train operations are not impacted by the global outage, though some MTA customer information systems are temporarily offline.
Global IT outages have also been reported in many countries across the world including Berlin Airport in Germany, the London Stock Exchange, Google Cloud, Microsoft and Gatwick Airport in the United Kingdom.
"We're investigating an issue impacting users ability to access various Microsoft 365 apps and services," Microsoft said in a statement released on social media Friday morning.
Airlines are now beginning to slowly come back online, but it is expected to take time before they are back up and fully operational. Delays and cancellations are expected through the morning and into the early afternoon.
Thousands of flights were canceled in the U.S. after American Airlines, United and Delta asked the FAA for global ground stop on all flights, according to an alert from the FAA.
At least 2,537 flights were canceled and 8,376 were delayed in the U.S., FlightAware data reported as of 4 p.m. ET Friday.
The airlines with the highest rate of cancellations and delays so far are Delta and American. Delta has 331 cancellations and 194 delays. In its most recent update, Delta said that it has resumed some flight departures.
Atlanta's Hartsfield-Jackson International Airport and Chicago O’Hare International are the two airports seeing the largest number of delays and cancellations.
"No one here knows anything, the gate agents said we all know as much as they do," an airline passenger told ABC News, saying his flight from SeaTac Airport in Washington was delayed for two hours on the tarmac before passengers were deplaned. "I feel awful for the employees and those that have a sick loved one they need to get to or funerals, thankfully that's not us."
The FAA told air traffic controllers to tell airborne pilots that airlines are currently experiencing communication issues. Meanwhile, flights that were in the air already were allowed to continue on, but no American, United or Delta flights had been taking off during the outage.
"We're aware of a technical issue with CrowdStrike that is impacting multiple carriers. American is working with CrowdStrike to resolve the issue as quickly as possible and apologize to our customers for the inconvenience," American Airlines said in a statement obtained by ABC News.
"A third party software outage is impacting computer systems worldwide, including at United," United Airlines said in a statement on Friday morning. "While we work to restore those systems, we are holding all aircraft at their departure airports. Flights already airborne are continuing to their destinations."
President Joe Biden was briefed on the CrowdStrike outage and his team is in touch with the company and impacted organizations, the White House said Friday.
"His team is engaged across the interagency to get sector by sector updates throughout the day and is standing by to provide assistance as needed," the White House said.
"The White House is in regular contact with CrowdStrike’s executive leadership and tracking progress on remediating affected systems. We have offered US government support. Our understanding is that this is not a cyber attack, but rather a faulty technical update. The White House has been convening agencies to assess impacts to the US government’s operations and entities around the country," a senior Biden administration official told ABC News.
The stock price of CrowdStrike plummeted in early trading on Friday amid a global IT outage that has affected clients worldwide. Shares fell nearly 15% on Friday morning, dropping the price to its lowest level since May.
-ABC News' Ahmad Hemingway, Sam Sweeney, Aaron Katersky, Joe Simonetti, Zunaira Zaki and Helena Skinner contributed to this report.