Delta Air Lines Joins CrowdStrike, Says It Lost $500 Million

Delta Air Lines expressed its frustration with CrowdStrike in a new letter Thursday, as the two airlines continue to trade blows following last month's massive global network outage.

The US-based airline has accused the cybersecurity firm of “negligence”, saying it had to cancel thousands of flights due to the outage and lost at least $500m (£392m) as a result.

CrowdStrike denied full responsibility for the Delta flight disruptions, which it said continued after other airlines had returned to service.

Delta has since been hit with a class action lawsuit filed on behalf of affected passengers.

The global issue was caused by CrowdStrike on July 19, after it sent a corrupted software update to a large number of its customers.

Microsoft estimated that 8.5 million Windows devices worldwide were disabled as a result.

Delta's services were affected for several days after the outage, even after other airlines appeared to have recovered. Delta canceled about 7,000 flights over five days through July 24, and the disruptions are now under investigation by the U.S. Department of Transportation.

The airline has since blamed CrowdStrike and Microsoft for the disruptions, and has threatened legal action against both companies.

Both CrowdStrike and Microsoft have denied claims that they were responsible for the disruptions at Delta.

Delta CEO Ed Bastian wrote in a filing with the U.S. Securities and Exchange Commission on Thursday that what happened was “unacceptable.”

“Our customers and employees deserve better,” Bastian wrote, adding that the technology outage affected 1.3 million Delta customers.

CrowdStrike said Sunday it would defend itself “vigorously” if Delta takes legal action against it.

Microsoft also said it would respond, adding that its initial review showed that Delta, unlike its competitors, was running on an outdated IT infrastructure.

In response, David Boies, an attorney representing Delta, wrote in a letter to CrowdStrike on Thursday that “there is no basis — whatsoever — to suggest that Delta was in any way responsible for the defective software that led to the downing of systems worldwide.”

He added that Delta Air Lines had invested billions of dollars in its technology, and said that it had had difficulty restoring operations because of its reliance on Microsoft and CrowdStrike.

In response, a CrowdStrike spokesperson accused Delta of promoting a “misleading narrative.”

Delta faces its own legal challenges following the outage, with a lawsuit filed against it on behalf of passengers whose flights were canceled.

“No other U.S. airline has cancelled even a tenth of that number of flights,” the lawsuit states.

The company also alleged that Delta failed to adequately compensate passengers, and that it required passengers to sign waivers releasing Delta from all legal claims.

Many airlines rely on Microsoft’s Office365 software to schedule flights. The CrowdStrike outage took down those systems, forcing them to resort to manually scheduling flights.

Since then, CrowdStrike has been sued by shareholders, who have accused the company of making “false and misleading” statements about its software testing. CrowdStrike has denied the allegations.