American Airlines flights at three airports were ground stopped due to technical issues at the airline, but the issues have since been resolved.
The advisory in the Federal Aviation Administration database cited "airline issues" as reason for the stop.
A spokesperson for American Airlines told TIME in an email just after 2 pm ET, “We have resolved connectivity issues that led to a ground stop today at our Chicago, Dallas/Fort Worth and Miami hubs. We apologize for the inconvenience and are working to get our customers on their way as soon as possible.”
The FAA confirmed on Twitter that the outage affected Dallas/Fort Worth International Airport, O'Hare International Airport, and Miami International Airport due to computer issues.
Passengers took to social media to complain vocally about the delays: