Spirit Airlines said Monday the cancellation of more than 2,800 flights over an 11-day stretch this summer cost the budget airline about $50 million in lost revenue and caused spending to soar.

The airline said the service meltdown that started in late July and a rise in COVID-19 cases are causing more last-minute cancellations and softer bookings.

Spirit said that it will reduce flights — it called them moves “tactical schedule reductions” — for the rest of the quarter, which ends Sept. 30.

The Miramar, Florida-based airline made the disclosures in a regulatory filing after the stock market closed.

The shares fell more than 2% in after-market trading.

Spirit said it canceled 2,826 flights from July 30 through Aug. 9 as it dealt with “overlapping challenges” including bad weather, airport staffing shortages, and crews being stranded far from their assigned flights.

On some days during that stretch, the cancellations amounted to more than 60% of the airline’s schedule.