Last Friday, 8.5 million computers around the world stopped working. All kinds of businesses were impacted, from airlines to banks to hospitals. The cause was a routine update sent out by a software company called CrowdStrike. WSJ’s Robert McMillan explains how the meltdown happened and why Microsoft’s software was especially vulnerable.

Further Reading:

- Blue Screens Everywhere Are Latest Tech Woe for Microsoft 

- CrowdStrike Made Its Name Fighting Technology Problems. Now It Has Caused One. 

Further Listening:

- The Computer Glitch That Caused Nearly 1,000 Convictions 

- Hacking the Hackers 

Learn more about your ad choices. Visit megaphone.fm/adchoices