Alaska Airlines operates 238 Boeing aircraft, 87 Embraer planes, and 45 additional planes through Horizon Air. The Seattle-based company is the fifth-largest airline in the U.S., serving more than 44 million passengers annually.

Alaska Airlines has resumed flights after the failure of a critical piece of hardware forced the airline to ground all its planes for approximately three hours, but the effects will linger into Monday, the company announced.

Alaska Airlines warned of more flight disruptions on Monday after an unexpected failure of a critical piece of hardware at its data centers late Sunday forced it to halt all flights for about three hours.