Numerous websites briefly go down in widespread outage

Major websites went down Thursday in what appeared to be a brief but widespread outage.

The websites of Airbnb, AT&T, Costco and Delta showed error messages in the morning hours. They seemed to be operating normally, however, by the afternoon.

Akamai, a major behind-the-scenes internet network company, said the disruption lasted about an hour and that it was due to a software update in the system that directs browsers to websites. It said there was no cyberattack.

"There's only a few big providers and occasionally they make little mistakes and this seems to be a case of they made a minor mistake," said Nicholas Weaver, a Ph.D., computer science lecturer at the University of California, Berkeley and cyber security expert. Adding that "When you do an update, if you do a bad update, that takes down a lot of computers."

Akamai said it was reviewing how it updates software to try to prevent outages in the future.