What Caused Such a Widespread Tech Meltdown?

An outage has hit computers around the world, affecting airlines, hospitals, retailers and other businesses. So how did that happen?

At the heart of it, there have been two issues in quick succession involving widely used Microsoft systems, and some users may have been affected by both of them.

On Thursday, some Microsoft clients in the central United States, including some airlines, were affected by an outage on its cloud service system, Azure. Microsoft’s cloud service status page indicated the company had identified a preliminary cause.

Some users may still be unable to access certain Microsoft 365 apps and services, including Teams video conferencing. The company was aware of the issue “affecting a subset of customers,” a Microsoft representative said in a statement. “We acknowledge the impact this can have on customers, and we are working to restore services for those still experiencing disruptions as quickly as possible.”

Separately, on Friday many Windows devices experienced problems involving CrowdStrike, according to the Azure status page. “We’re aware of an issue affecting Windows devices due to an update from a third-party software platform,” according to the representative. “We anticipate a resolution is forthcoming.”

That outage was caused by a flawed security update by CrowdStrike. George Kurtz, the company’s chief executive, said in a statement that it was “actively working with customers impacted by a defect found in a single content update for Windows hosts.” He added: “This is not a security incident or cyberattack. The issue has been identified, isolated and a fix has been deployed.”