U.S. regulators have launched an investigation into Delta Air Lines' prolonged recovery from a global technology outage caused by a faulty update from cybersecurity firm CrowdStrike. The issue has resulted in more than 6,500 Delta flight cancellations since last Friday, significantly more than any other airline. Transportation Secretary Pete Buttigieg announced the probe to assess why Delta is still canceling hundreds of flights and its treatment of passengers, which includes reports of unaccompanied minors being stranded and long customer service lines. Delta has stated it is focusing on restoring normal operations by the end of the week and is cooperating with the investigation. The outage impacted many businesses globally, but most airlines returned to normal operations quickly, leaving Delta's extended disruptions particularly concerning.