Delta Airlines expressed its frustration with CrowdStrike in a new letter on Thursday as the two companies continue to trade blows following last month’s massive global network outage.
The US airline accused the cybersecurity company of “negligence” and said the outage forced it to cancel thousands of flights, costing it at least $500 million (£392 million).
CrowdStrike had denied that it was solely responsible for the disruptions to Delta’s flight operations, which it said continued even after other airlines were back online.
Delta has since faced a class action lawsuit filed on behalf of affected passengers.
The global bug originated on July 19th from CrowdStrike after the company sent a corrupted software update to its numerous customers.
Microsoft estimates that 8.5 million Windows devices were disabled worldwide as a result.
Delta Airlines’ operations were disrupted for days after the outage, even after other airlines appeared to recover. Delta canceled about 7,000 flights over five days ending July 24 and is now being investigated by the U.S. Department of Transportation over the disruptions.
The airline has since blamed CrowdStrike and Microsoft for the disruptions and threatened legal action against the two companies.
Both CrowdStrike and Microsoft have denied allegations that they were responsible for the disruptions at Delta.
Delta CEO Ed Bastian wrote in a letter to the U.S. Securities and Exchange Commission (SEC) on Thursday that the incident was “unacceptable.”
“Our customers and employees deserve better,” Bastian wrote, adding that 1.3 million Delta customers were affected by the technology breakdown.
CrowdStrike said on Sunday that the company would defend itself “aggressively” if Delta took legal action against the company.
Microsoft also announced a fightback, adding that a preliminary investigation shows that Delta, unlike its competitors, is working with an outdated IT infrastructure.
In response, Delta’s attorney, David Boies, wrote in a letter to CrowdStrike on Thursday: “There is no basis – none whatsoever – to believe that Delta was in any way responsible for the faulty software that caused systems around the world to crash.”
He added that Delta Airlines has invested billions of dollars in its technology and said its dependence on Microsoft and CrowdStrike has made it difficult to resume operations.
In response, a CrowdStrike spokesperson accused Delta of spreading “a misleading narrative.”
Delta is facing legal challenges following the outage after a lawsuit was filed against the company on behalf of passengers whose flights were canceled.
The lawsuit stated that “no other U.S. airline has canceled even one-tenth as many flights.”
It was also alleged that Delta failed to pay adequate compensation to its passengers and that passengers were asked to sign waivers releasing Delta from all legal claims.
Many airlines rely on Microsoft Office 365 for planning. The CrowdStrike outage crashed those systems and forced them to resort to manual planning.
CrowdStrike has since been sued by its shareholders, who accused the company of making “false and misleading” statements about its software testing. CrowdStrike has denied the allegations.
