NEW YORK (Reuters) - Angry passengers and a U.S. senator pressed Sun Country Airlines for answers on Monday after the regional airline left more than 200 people stranded in Mexico after canceling two flights on Saturday due to a Midwest blizzard.

Eagan, Minnesota-based Sun Country, which was scheduled to end its seasonal service to Mexico on that day, refused to put on replacement flights or book passengers on other airlines, as carriers usually do when flights are canceled because of bad weather.

That meant passengers booked on two Saturday flights from Mazatlan and Cabo San Lucas in Mexico to Minneapolis-Saint Paul International Airport - which was closed when the flights were due to land - had to find their own flights back to the United States.

“These were our last flights for the season, so we do not have another flight to re-accommodate passengers on. You will receive a full refund,” the airline wrote to passengers on its Facebook page on Sunday. “Flights will need to be purchased on another carrier. We apologize for any inconvenience this may cause.”

Stranded passengers flooded the carrier’s social media pages, complaining about the cancellations and the airline’s slow response to calls to its customer service line.

“‘Inconvenience’ doesn’t even begin to describe the nightmare you left us in by REFUSING to help the 240 people you STRANDED in Cabo yesterday,” Facebook user Derek William wrote on Sunday. “I can assure you I will NEVER fly your airline again.”

Twitter user Brandon Larson wrote: “They flew us down here and are ending their service to Los Cabo Mexico—they are not coming back to get us!” His message was retweeted 21 times and liked 34 times.

Sun Country made a fuller apology late on Monday, after the social media backlash.

“We cannot apologize enough to those passengers who were hit by the one-two punch of an April snowstorm and the seasonality end-date of our winter schedule,” the airline’s Vice President of Marketing Kelsey Dodson-Smith said. “Our fleet was already allocated to fly other operations and unfortunately, we were unable to send additional aircraft to Los Cabos and Mazatlán without cancelling more flights causing further disruptions to more of our passengers.”

By Monday afternoon, the incident had attracted the attention of federal lawmakers, with Minnesota Senator Tina Smith writing to the U.S. Department of Transportation, demanding it investigate Sun Country’s “failures.”

In the letter, which the senator made public, she asks for an explanation of what is being done to ensure airlines implement cancellation policies that protect consumer interests.