The systemwide outage that grounded Delta flights for three days last month cost the company approximately $100 million in revenue, the company said in its latest monthly report.

The outage resulted in 2,300 canceled flights over the three days; the revenue impact came from both the outage and subsequent operational recovery efforts, Delta said.

Overall, passenger unit revenue for Delta fell by 9.5 percent year over year last month, with other factors including pressure from close-in domestic yield weakness, the ongoing supply-demand imbalance in the Transatlantic, and headwinds from its Yen hedge positions.

“We are grateful to our customers for continuing to rely on Delta for the superior customer service and operational performance you’ve come to expect from us,” said Ed Bastian, CEO of Delta Air Lines. “Our recovery effort exemplified the hard work and determination of Delta people worldwide, and all 80,000 remain dedicated to regaining your trust.”