Over 400 flights were delayed or canceled at Sea-Tac Airport due to an Alaska Airlines IT outage. The outage was caused by an unexpected hardware failure at Alaska Airlines' data centers. Alaska Airlines flights have resumed, and passengers are asked to check their flight status before heading to the airport.

Alaska Airlines flight cancellations and delays grew Monday after the carrier requested a ground stop during an outage Sunday night.

A system-wide ground stop was issued for Alaska Airlines and Horizon Air flights at Sea-Tac Airport Sunday night after an IT outage disrupted operations.