The outage began just after 6 p.m. ET and was resolved a few hours later, though delays are expected to continue into the night.

United Airlines flights at San Francisco International Airport (SFO) were grounded Wednesday evening due to a “technology issue,” the airline said in a statement. As of 6:20 p.m., the ground stops for United flights have been lifted,

United Airlines flights at Denver International Airport and other major American airports are grounded because of a “technology issue,” airlines officials said Wednesday night.