Airline booking engines and Google Flights hit with major outage

• United, Delta, and American Airlines appeared to be down for some users on Monday.
• The outage appears to have originated on a Google-run system that many US airlines use.

Reports by users showed issues on Monday afternoon with the websites of Delta Air Lines and American Airlines, according to Downdetector.com.

People familiar with the matter said there seemed to be an outage on ITA, a system run by Google that many U.S. airlines use for their bookings. United Airlines and Google Flights also appeared to be impacted by the issue.

A Google spokesperson confirmed the outage, telling ABC News reporter Sam Sweeney that "there is a known issue on our side and we are working now to implement a fix."

United Airlines told Insider it is "working to address an issue with united.com and the mobile app preventing customers from searching for flights. We expect to have a resolution soon."

This story is developing...