Alaska Airlines has successfully resolved a tech systems outage that caused its entire fleet to be grounded for three hours on Sunday night. The airline announced the fix in a statement early Monday morning, stating that operations have resumed.

The IT outage, which was first reported around 11 p. m. ET, affected both Alaska Airlines and its subsidiary Horizon Air. The airline released a statement acknowledging the issue and requested a temporary ground stop until the problem could be resolved.

While the nature of the IT outage was not disclosed, it caused significant delays and cancellations for Alaska Airlines flights. According to FlightAware’s tracker, at least 46 flights were delayed and 50 were canceled as of Monday morning. Passengers who had already boarded their flights were stuck onboard for over an hour before being deplaned.

The Federal Aviation Administration also issued an advisory, stating that the ground stop initially only applied to Alaska Airlines flights, but was later expanded to include Horizon Air flights as well.

In response to the situation, Alaska Airlines advised passengers traveling on Sunday night to check the status of their flights before heading to the airport. The airline also warned that there may be residual impacts on flights as they work to reposition aircraft and crews. As of Monday morning, operations are slowly returning to normal.

Alaska Airlines has a total of 233 passenger planes in its fleet, all of which are variants of the Boeing 737 and the newer 737 Max family. The airline also has five air freighters in its fleet. Its subsidiary, Horizon Air, operates 45 smaller regional jets made by Embraer.

In conclusion, Alaska Airlines has successfully resolved the IT outage that caused significant disruptions to its operations on Sunday night. As the airline works to get back on track, passengers are advised to check the status of their flights before heading to the airport.