Alaska Airlines temporarily grounded its fleet late Sunday. It’s a reminder of the threat posed to the sector by tech outages.

The request to federal authorities kept Alaska and Horizon flights out of the air until the FAA said the stop was lifted after 2 a.m. ET. Monday.

Alaska Airlines said its operations have resumed after a temporary ground stop was issued on all its flights and those of a regional subsidiary Horizon Air due to an IT outage, the company said Sunday evening.