Delta Air Lines cut its third-quarter revenue forecast on Thursday following the flight cancellations and business disruptions caused by a global cyber outage in July.

A software update in July by global cybersecurity firm CrowdStrike triggered system problems for Microsoft customers, including many airlines.

The disruptions persisted at Delta and the Atlanta-based carrier canceled about 7,000 flights over five days. It faces an investigation from the U.S. Transportation Department for the disruptions.

The airline now expects current-quarter revenue in the range of flat to up 1%, compared with a 2% to 4% growth projected earlier.

Delta had said it expects a direct revenue hit of $380 million from the outage in the current quarter owing to refunds it owes to customers for canceled flights and compensation in cash and frequent flyer miles.

It also reported additional expenses of $170 million related to customer expense reimbursement and crew-related costs.