The New York Times website crashed and remained unaccessible for much of the day on Wednesday.
Spokeswoman Danielle Rhodes Ha told the Canadian Press that the newspaper was looking into the cause, but offered few details.
The website went down late Wednesday morning.
The company's newspaper and corporate sites also appeared to be unreachable. Emails sent to New York Times email addresses were returned as undeliverable.
"The New York Times Web site is experiencing technical difficulties. We expect to be back up shortly," said the Times in a message sent from its official Twitter account just before noon on Wednesday.
When the site returned later in the day, a message to readers said it happened just before scheduled maintenance.
"As you may know, our Web site was unavailable for a period of time earlier today. The outage occurred within seconds of a scheduled maintenance update, which we believe was the cause. We are working on fully restoring service and apologize for any inconvenience," a short message said.
While the site was unavailable, stories were posted to the Times' Facebook page.
The Canadian Press contributed to this report.