City of Toronto, Canada

Global technology disruptions grounded flights, disrupted hospitals and blocked border crossings in Canada on Friday, as reported problems persisted hours after issues with Microsoft services were resolved.

Cybersecurity firm CrowdStrike said the issue it believes caused the outage was not a security incident or cyberattack. The problem affects Microsoft 365 apps and services, and the growing problems continue after the tech company announced it would resolve it in phases.

Toronto Pearson International Airport and Montreal-Trudeau International Airport have both said power outages could cause flight delays and cancellations.

Porter Airlines announced it was canceling flights until noon ET due to the power outage.

Meanwhile, Air Canada said there was no major impact on its operations, adding that it was monitoring the situation closely.

The University Health Network, one of Canada’s largest hospital networks, said some of its systems were affected by the outage. In a social media post, it said clinical operations were continuing as planned, but some patients may experience delays.

Windsor police reported lengthy delays at the Canada-U.S. border crossing at the Ambassador Bridge and the Detroit-Windsor Tunnel.

The Newfoundland and Labrador government is warning “users of its digital platforms” of possible service disruptions. The provincial health authority, NL Health Services, said its IT services have also been affected, including key information systems used to manage patient care and financial information.

Some companies said their operations were unaffected by technological disruptions.

Rogers Communications Inc. said there was no impact to its telephone and internet networks or media channels. Air Canada said there was no major impact to its operations, but the airline was monitoring the situation closely.

Microsoft 365 released on social media platform

CrowdStrike said in a statement emailed to The Associated Press that the company is “actively working with customers affected by a vulnerability discovered in a content update for Windows hosts.”

With files from the Associated Press

This report by The Canadian Press was first published July 19, 2024.