SEATAC, Wash. — Alaska Airlines and Horizon Air have resumed operations after a temporary nationwide ground stop, but thousands of passengers remain stranded, unsure when they’ll reach their destinations.

The halt, triggered by an IT outage around 8 p.m. Sunday, lasted three hours before being lifted at 11 p.m. The airline blamed the disruption on "the unexpected failure of critical third-party hardware,"which forced a complete pause in flights.

"While the ground stop has been lifted, we anticipate ongoing delays as we reposition aircraft and crews," the airline said in a statement. "Full recovery will take time."

Since Sunday evening, the outage has disrupted travel for 13,500 passengers, with nearly 200 flights canceled, causing cascading delays across the airline’s network.

Passengers described scenes of frustration and exhaustion. Paul Davis, en route to Texas, was stuck in Seattle after pilots announced the IT failure. "Right away, we knew something was wrong," he said.

Katie Holland, traveling from Juneau to Orlando, spent hours in lines only to face cancellations. "I waited five hours, then my flight was canceled. This morning, I stood in line for seven hours just to get my luggage," she said. "I just want to go home—I’m completely burnt out."

For many, the ordeal took an emotional toll. "Absolute misery. One of the worst days of my life," Davis said. "I’m exhausted—I just need sleep."

As Alaska Airlines works to normalize operations, passengers brace for further delays in an already chaotic travel week.