An early morning power outage in Atlanta caused serious computer system issues for Delta, resulting in flight delays and cancellations for the airline’s flights throughout the globe today.

While the Delta ground stop was lifted as of 8:40 a.m. ET, the airline says that travelers on the airline can expect delays and cancellations, and that it may take longer than usual to update accurate flight status at, the Fly Delta app, and from airline reps on the phone and at the airport. All flights that were en route when the outage happened are operating normally, according to the airline.

The airline also has published a waiver for customers traveling August 8–12 that entitles passengers on affected flights to a refund or a free one-time ticket change.