Alaska Airlines has revealed that an "unexpected failure" of a critical piece of hardware caused an IT outage that led to its entire fleet being grounded.

Alaska Airlines has revealed that its "significant" IT outage on Sunday night was not caused by hackers, but by hardware at one of its data centers failing.

Alaska Airlines stated that the IT outage resulted in a “temporary, system-wide ground stop for Alaska Airlines and Horizon Air flights” around 11 p.m. ET and lasted until 2 a.m. Monday, the airline wrote in a statement on X.