(Reuters) – Delta Air Lines will take a loss of $500 million due to the CrowdStrike (NASDAQ:) outage, the carrier’s Chief Executive Ed Bastian said in an interview with CNBC on Wednesday.

The airline has been the slowest to recover among enormous U.S. carriers after a technical failure on July 19 led to the cancellation of more than 2,200 flights.

Bastian apologized to Delta customers and added that the airline, which relies heavily on technology services from Microsoft (NASDAQ:) and CrowdStrike, was hit hardest by the outage.

Analysts estimate the impact on Delta’s financial results will be hundreds of millions of dollars.

CNBC reported earlier this week that Delta has hired a law firm and intends to seek damages from Microsoft and CrowdStrike for the outage.

Last week, the U.S. Department of Transportation also announced it was opening an investigation into Delta for canceling flights due to the outage.