ATLANTA, Ga. — Delta Air Lines said delays and cancellations will potentially last through the weekend after an IT outage involving Microsoft systems.

The Atlanta-based airline said more than 1,200 Delta mainline and Delta Connection flights were canceled Friday due to a “vendor technology” issue.

Airline officials said canceling a flight is always a last resort. The company is extending its travel waiver to all customers who had flights booked to leave on Friday. Delta is notifying customers about delays and cancellations in their itinerary via the Fly Delta app.

No one under the age of 18 can fly alone until July 21. Meal vouchers and hotel accommodations are being provided to impacted customers.

The outage is related to an issue that is blocking access to Microsoft apps and services after CrowdStrike, a global cybersecurity firm, pushed out an update.

The issue is impacting everything from hospitals to federal offices to businesses. It’s unclear when the issue will be resolved.