# 2024 Delta Air Lines disruption

In mid July 2024, Delta Air Lines, a major U.S. carrier and the largest airline in the world by revenue, assets, market capitalization experienced an operational disruption following the 2024 CrowdStrike incident including the cancelation of over 1,200 flights. The crisis began on the morning of Friday, July 19 when a ground stop was issued by major carriers but while other carriers quickly recovered, the crisis continued for Delta with the airline finally resuming normal flight operations on July 25. Delta confirmed that the crisis resulted in the cancellation of over 7,000 flights over the five days of the disruption affecting over 1.3 million passengers.
In the aftermath of the Delta disruption, the United States Department of Transportation opened an investigation into Delta for potential violations of consumer rights.

## Background

In the mid-morning of July 19, a ground stop was issued by the three major U.S. carriers, United, Delta, and American Airlines, halting takeoffs but allowing aircraft aloft to reach their destinations. Other carriers internationally were also affected. Around 10:30 a.m. Eastern time, AP reported that about 1,500 flights had already been cancelled in the United States due to the outage. While American Airlines, United, and other carriers internationally recovered relatively quickly after Friday, Delta, by far the hardest hit of the US major airlines, experienced an operational disruption that continued for multiple days past the incident.

## Timeline

On July 19, cybersecurity company CrowdStrike distributed a faulty update to its Falcon Sensor security software that caused widespread problems with Microsoft Windows computers running the software. As a result, roughly 8.5 million systems crashed and were unable to properly restart in what has been called the largest outage in the history of information technology and "historic in scale". This resulted in flight disruption globally with 5,078 flights, 4.6% of those scheduled that day, cancelled. An unrelated Microsoft Azure outage, affecting services such as Microsoft 365, compounded airlines' problems. However, while other airlines quickly recovered operations, Delta Air Lines did not.
Over 1,200 Delta Air Lines flights were canceled on July 19. Thousands of stranded travelers were forced to spend the night at Hartsfield–Jackson Atlanta International Airport, Delta's largest hub and the busiest airport in the world by passenger traffic. Metro Atlanta hotels and rental car companies were overwhelmed by the crisis, leaving travelers no option but to stay in the airport. One traveler attempting to return home to Tampa (after giving up on reaching California) reported that Amtrak was charging $1,000 for a one-way train ticket from Atlanta to Tampa. Visibly distraught passengers with nowhere to go were seen trying to sleep in the airport on hard linoleum floors without blankets or food. The airport's custodial staff were also overwhelmed, with restrooms and trash reportedly "out of control". Without warning, Delta banned unaccompanied minors on its flights through the end of July 23. This imposed hardship on parents who had been counting on that service to enable their children to fly without the expense of an accompanying adult.
While other carriers recovered, the crisis continued for Delta with more than 1,400 flights cancelled on July 20 followed by more than 1,300 flights on July 21. With so many passengers still stuck in Hartsfield–Jackson after two consecutive nights, the airport implemented a "concessions crisis plan" and a plan to reunite passengers with their checked baggage. However, passengers in Atlanta continued to report "jam-packed" conditions and "heartbreaking" scenes in the terminals.
On July 21, Delta CEO Ed Bastian apologized to customers in a statement and revealed that the outage had left one of Delta's crew-tracking software programs "unable to effectively process the unprecedented number of changes triggered by the system shutdown". Delta CIO Rahul Samant said the program had been brought back online around 11 a.m. on July 19, but was overwhelmed by the backlog of updates awaiting processing and had been trying to catch up ever since. After the ground stop left too many crew members in the wrong places, Delta struggled to assemble enough pilots and flight attendants at airport gates to operate scheduled flights.
Many flights were repeatedly delayed and finally canceled because the one or two crew members who made it to the gate for a particular flight kept hitting their legal flight time limit before the airline could finish fully staffing the flight, and this caused the crisis to snowball as those crew and their aircraft were now in the wrong place for the following day's flights. A similar phenomenon occurred during the 2022 Southwest Airlines scheduling crisis. That same day, US Secretary of Transportation Pete Buttigieg said on social media that the US Department of Transportation had received hundreds of complaints about Delta, and reminded the airline of its legal obligations to affected passengers.
On July 22, Delta cancelled more than 1,200 flights. On 23 July, the Department of Transportation announced the launch of a formal investigation into Delta's treatment of passengers. Delta officials promised to cooperate but said the airline was focused on its recovery.
Senator Maria Cantwell, in her capacity as chair of the Senate Committee on Commerce, Science, and Transportation, wrote to Bastian to demanding that Delta stop failing to fulfill its obligations under law. Meanwhile, Rep. Rick Larsen, the ranking member of the House Committee on Transportation and Infrastructure, released a statement alleging "families across the country are still stranded at airports due to last week’s global technology outage, and the slow response by some airlines to this meltdown has been unacceptable."
On July 23, Secretary Buttigieg estimated that over 500,000 passengers had been affected by Delta flight cancellations. He told a press conference, "There's a lot of things I'm very concerned about, including people being on hold for hours and hours, trying to get a new flight, people having to sleep on airport floors, even accounts of unaccompanied minors being stranded in airports, unable to get on a flight". He told CBS News: "Stories about people in lines of more than a hundred people with just one customer service agent serving them at an airport, that's completely unacceptable." By then, numerous passengers had ended up in different airports than their baggage because of Delta's flight cancellations, resulting in large piles of unclaimed suitcases and other checked baggage at Delta's airport terminals around the world.
On July 25, Delta reported to have returned to normal flight operations, after having to cancel nearly 7,000 flights.

## Aftermath
### Financial cost

Following the disruption, Delta CEO Ed Bastian said the disruption had cost the airline $500 million. On August 9, Delta confirmed in a filing with the US Securities and Exchange Commission that over 7,000 flights had been cancelled over five days, and estimated its losses at $380 million in lost revenue and $170 million in expenses (adding up to about $550 million). Delta also estimated that around 1.3 million passengers had been affected by the flight cancellations.

### U.S. Department of Transportation investigation

The United States Department of Transportation's Office of Aviation Consumer Protection opened an investigation into Delta Air Lines noting "continued widespread flight disruptions and reports of concerning customer service failures" while other carriers returned to normal levels of service.
During the disruption, passengers had filed more than 5,000 complaints about Delta with the Department of Transportation.
Secretary of Transportation Pete Buttigieg stating that "All airline passengers have the right to be treated fairly, and I will make sure that right is upheld". The Washington Post reported that the department was investigating allegedly misleading communications from Delta that offered only credit towards future Delta flights as compensation for cancelled flights and failed to clearly notify passengers of their legal right to a cash refund.
Buttigieg noted that Delta had failed to take care of consumers during its operational collapse. The Department of Transportation's previous investigation into the 2022 Southwest Airlines scheduling crisis resulted in a $140 million fine for Southwest.

### Class action suit

In August 2024, passengers left stranded and refused refunds by Delta filed suit seeking class action status. The lawsuit alleged that "Delta’s failure to recover from the CrowdStrike outage left passengers stranded in airports across the country and the world and, in many cases, thousands of miles from home" with "disastrous" impact.

### Delta Air Lines vs. CrowdStrike Lawsuit

On October 25, 2024, Delta Air Lines filed a lawsuit against cybersecurity firm CrowdStrike, seeking compensation for losses incurred during a significant IT outage on July 19, 2024. Delta estimates the financial impact at around $550 million, encompassing both lost revenue and additional expenses. The airline contends that CrowdStrike's negligence in software testing and deployment directly resulted in the operational disruptions. In response, CrowdStrike has acknowledged the faulty update but disputes the extent of its liability, attributing Delta's prolonged recovery to the airline's internal IT management. This legal action underscores the critical importance of robust cybersecurity measures in the aviation industry.

### Reputational damage

Delta's response to the operational disruption significantly undermined Delta's reputation with consumers. Analysts noted that melting down while peers returned to normal operations had damaged Delta's image as a reliable carrier.