Global technology issues from Friday may still have lasting effects at airports nationwide almost a week later.

The U.S. Department of Transportation (USDOT) opened an investigation into Delta Air Lines Tuesday morning to make sure the airline is following the law and taking care of passengers during continued widespread disruptions.

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Delta apologized for the disruptions as they continue their operational recovery, and they are offering some assistance.

"We anticipate cancellations Wednesday to be minimal. Thursday is expected to be a normal day, with the airline fully recovered and operating at a traditional level of reliability," said Delta CEO Ed Bastian.

Overall, the airports this year have been extremely busy. The Transportation Security Administration (TSA) says the top 10 busiest days ever have all been this year. The third busiest was the day before the global outage on Thursday. TSA says they screened nearly 2.96 million people at airports nationwide.