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Delta Air Lines is still reeling from the fallout of the global IT outage, canceling more flights as it struggles to get back on track after the disruption.
The airline cancelled 700 flights Monday, which comprise 19% of its mainline operation, CNBC reported
Since the outage on Friday, the airline had already canceled 4,600 flights till Sunday, offering frequent flyer miles to travelers due to the flight cancellations. Aviation data firm OAG revealed Delta has canceled more flights than any other airline.
The increasing cancellations have led to Delta facing criticism from Transportation Secretary Pete Buttigieg.
"We continue to receive reports of unacceptable disruptions and customer service conditions at Delta Air Lines, including hundreds of complaints filed with our Department," Buttigieg said, CNBC reported.
He added that he has urged the airline to provide passengers with prompt refunds, as well as timely reimbursement for food. Buttigieg said the airline should also ensure "overnight hotel stays to consumers affected by the delays and cancellations, as well as adequate customer service assistance to all of their passengers."
In a statement, Delta Air Lines CEO Ed Bastian apologized to the customers impacted by the cancellations.
"Delta is in the business of connecting the world, and we understand how difficult it can be when your travels are disrupted," he added.
Bastian wrote Delta had a number of Microsoft tools that were affected by the outage.
"Delta has a significant number of applications that use that system, and in particular one of our crew tracking-related tools was affected and unable to effectively process the unprecedented number of changes triggered by the system shutdown."
However, he promised, "Our teams have been working around the clock to recover and restore full functionality."
According to Raymond James, a research firm, Delta is expected to take a hit financially to the tune of $160 million.
While other airlines have slowly started to recover, Buttigieg said that the airline still experiences "continued disruptions and unacceptable customer service conditions," according to the Washington Post.
The global outage had affected Windows users, who were running the CrowdStrike Falcon cybersecurity software. An update released by CrowdStrike had caused a system crash, leading to the computers displaying the "blue screen of death" fatal error message.