is recovering from what could only be described as a meltdown. The carrier canceled so many flights last week that the Department of Transportation is reportedly monitoring its response.

Airlines canceled thousands of flights this summer . Spirit, like other airlines, as reasons why it couldn’t keep its flights going. The airline’s failure is so bad that, as by the Points Guy, the DOT is monitoring the airline’s recovery.

Spirit canceled more than 2,000 flights last week. On some days, the airline canceled up to 60 percent of its daily schedule. Airports were clogged with thousands of passengers and crew who didn’t have flights to board. This is reportedly drawing the ire of the DOT, from the Points Guy:

A source at DOT, with knowledge of the situation, confirmed to TPG that the department has been in contact with Spirit in regards to the airline canceling as many as 60% of its daily flights over six days last week, “reminding” the airline of its obligations to customers under federal law.

The DOT is also continuing to watch Spirit’s response to ensure that it complies with those laws and responds appropriately, a DOT spokesperson confirmed.

The cancelations are the result of the airline running with no margin for error, CNBC . Flight crews ran out of available working hours, leading to delays. Add in stormy weather and system delays and Spirit had the perfect recipe for mass cancellations.

Making matters worse is that, as NBC Philadelphia , a number of the stranded passengers had a hard time finding a way home. Spirit airport counter lines were long and some passengers couldn’t get Spirit Airlines on the phone to book an alternative flight.

Others were offered rescheduled flights a number of days into the future. The airline is also sending $50 vouchers to some passengers of canceled flights. Passengers to a refund when their flight is canceled and the airline is unable to get them onto a new flight. Spirit Airlines CEO Ted Christie and Spirit’s Director of Communications Erik Hofmeyer both say that the airline is working through getting passengers refunds.

I reached out to the DOT for additional clarification and will update if I hear back. The good news is that the airline is having a much better week this week, with only a small handful of flights canceled thus far.