Air travel was significantly disrupted at Seattle-Tacoma International Airport (SEA) on Sunday evening after an IT outage forced Alaska Airlines to initiate a temporary ground stop for all of its flights.
The system-wide halt, which also affected Horizon Air operations, began around 8:00 p.m. and lasted until approximately 11:00 p.m. on Sunday, July 20. By the time the ground stop was lifted, hundreds of passengers faced delays or cancellations as the airline scrambled to restore normal operations.
According to Alaska Airlines, the disruption stemmed from a hardware failure at its data centers. The airline confirmed that a critical piece of equipment—built by a third-party vendor and designed to be multi-redundant—unexpectedly failed, impacting several internal systems. While the outage was severe, the airline clarified that there was no evidence of hacking or malicious activity.
“This issue was caused by an unexpected failure of a critical component in our infrastructure,” Alaska Airlines told the Associated Press. “We are working closely with the manufacturer to replace the hardware and ensure system stability.”
The ripple effect of the outage was evident at Sea-Tac Airport. On Sunday alone, 45 Alaska Airlines flights departing from Seattle were canceled and 211 were delayed. By midday Monday, another 54 cancellations and 112 delays had been reported as the airline worked to reset its operations.
Flights have since resumed, but recovery is expected to take time. Alaska Airlines is repositioning aircraft and crews, and has activated a flexible travel policy for affected passengers. The airline is advising customers to check their flight status online before heading to the airport.
With flight disruptions expected to continue intermittently during the recovery period, officials urge travelers to plan ahead and remain patient.
