LAS VEGAS (KLAS) — The U.S. Department of Transportation announced Monday evening that it will examine whether or not Southwest Airlines is complying with its customer service plan amid major flight cancellations and delays.

Travelers nationwide have been experiencing a nightmare due to a winter storm making its way across parts of the country.

As of 9 p.m. Monday, nationally 8,291 flights were delayed and 3,973 were canceled within, into, or out of the United States, according to FlightAware, a flight tracking website.

However, out of those cancellations, 2,908 were by Southwest Airlines. The airline was also responsible for 663 of those delays, according to FlightAware.

In response, the USDOT announced in a tweet that it is going to examine how Southwest Airlines has handled this situation saying:

USDOT is concerned by Southwest’s unacceptable rate of cancellations and delays & reports of lack of prompt customer service. The Department will examine whether cancellations were controllable and if Southwest is complying with its customer service plan.

The U.S. Department of Transportation (@USDOT)

At Harry Reid International Airport in Las Vegas, there were a total of 291 delayed flights and 358 canceled flights as of Monday night, according to FlightAware.

Out of those flights Southwest was responsible for 43 delays and 291 cancellations.

Southwest Airlines released a statement on Monday that said they are working to recover from operational challenges and recognize “falling short.”

Southwest said in the statement that they are working with safety at the forefront of the “wide-scale” disruption by rebalancing the airline and repositioning crews and their fleet to serve those traveling with them.

“We were fully staffed and prepared for the approaching holiday weekend when the severe weather swept across the continent, where Southwest is the largest carrier in 23 of the top 25 travel markets in the U.S. These operational conditions forced daily changes to our flight schedule at a volume and magnitude that still has the tools our teams use to recover the airline operating at capacity,” the statement said. “This safety-first work is intentional, ongoing, and necessary to return to normal reliability, one that minimizes last-minute inconveniences. We anticipate additional changes with an already reduced level of flights as we approach the coming New Year holiday travel period. And we’re working to reach to Customers whose travel plans will change with specific information and their available options.”

The statement concluded by saying that they will work to make things right for those they have let down, including employees.

“With no concern higher than ultimate Safety, the People of Southwest share a goal to take care of each and every Customer. We recognize falling short and sincerely apologize,” the statement said.

Travelers can check Reid International’s flight arrivals and departures at this link. Airport officials continue to urge travelers to arrive at the airport at least two hours prior to the flight departure and to expect large crowds.