The global tech outage continues to wreak havoc on U.S. air travel, with over 2,500 flights canceled for the third consecutive day, leading to thousands of passengers stranded.

What Happened: On Sunday, about 1,700 flights within, into, or out of the U.S. were canceled, and over 9,000 flights were delayed, according to FlightAware.com. Delta Air Lines (DAL  ) accounted for over 1,000 of these cancellations.

The airline attributed the cancellations and delays to "an outside vendor technology issue" and offered travel vouchers, waivers, and SkyMiles Program miles to some affected customers, reported CNN.

Delta CEO, Ed Bastian, assured customers that the airline is working to restore operations. "Canceling a flight is always a last resort, and something we don't take lightly," Bastian said.

Major airlines, including United Airlines (UAL  ) and American Airlines (AAL  ), have reported service restoration, but further delays and disruptions are expected, the report noted.

Delta has suspended unaccompanied minor travel until Wednesday due to the outage. The U.S. Department of Transportation has deemed the flight delays and cancellations "controllable" and "attributable to the airline," requiring airlines to adhere to their customer service commitments.

Why It Matters: The tech outage, caused by a flawed software update for Microsoft Corporation (MSFT  ) Windows operating systems issued by CrowdStrike, affected an estimated 8.5 million devices worldwide.

The issue disrupted services across various sectors, including businesses, government agencies, health and emergency services, banks, schools, and universities.

Despite CrowdStrike Holdings, Inc. (CRWD  ) CEO George Kurtz's apology and assurance of a deployed fix, experts predict a lengthy recovery process.

This incident has resulted in a significant decline in CrowdStrike's stock price and has been deemed a "major black eye" for the cybersecurity firm.