DALLAS (AP) — Southwest Airlines is paying $140 million to settle a government investigation over a meltdown last holiday season that led to thousands of canceled flights.

The airline will pay a $35 million fine and get credit for compensation provided to travelers.

Transportation Secretary Pete Buttigieg said Monday the settlement shows his department will hold airlines accountable if they fail to treat customers properly.

The airline canceled nearly 17,000 flights as a winter storm paralyzed operations in Denver and Chicago and then snowballed when a crew rescheduling system couldn’t keep up.

Southwest says it didn’t violate consumer protection laws but is striking the agreement to settle the matter.