The Federal Aviation Administration issued a ground stop on Wednesday evening affecting United Airlines flights bound for Chicago.
The order impacted United flights in regional hubs across the country, including Denver, Newark, Houston, and San Francisco, the agency said.
“Due to a technology issue, we are holding United mainline flights at their departure airports,” United told NBC Chicago. “We expect additional flight delays this evening as we work through this issue. Safety is our top priority, and we’ll work with our customers to get them to their destinations.”
This is a breaking news story and will be updated with new information.