United Airlines flights on major routes were grounded Wednesday because of a technology issue, and additional flight delays were expected into the evening, the airline said.

A tech outage led United Airlines to ground flights nationwide Wednesday night, and even with the issue now resolved, over 1,000 flights have been delayed and dozens canceled.

The airline’s travel alert page notes that a technology disruption may impact flights to or from 14 airports including Newark, Washington, Los Angeles and Chicago.