Here's Sun Country's explanation for abandoning ticket-holders in Mexico

Weather canceled Sun Country's return flights; then the airline told its customers to figure out their own ways back.

Weather canceled Sun Country's return flights; then the airline told its customers to figure out their own ways back. Tom Sweeney, Star Tribune

Sun Country was founded by a group of Minnesota-based pilots and flight attendants, who thought people in the Upper Midwest might like homegrown options to fly to tourist-y locales.

Sun Country still runs a lot of those same flights out of the Minneapolis-St. Paul International Airport. Indeed, they recently delivered a few flights' worth of such passengers to popular destinations in Mexico: Cancun, Mazatlan, and San Jose del Cabo. Those fliers were in for a rude awakening, weather-wise, having traveled from sunny beach resorts to find the Twin Cities overcome by knee-deep snow.

On Saturday, that adjustment became the least of their worries, as Sun Country informed some passengers that Minnesota's snowstorm had canceled its flights ... the airline's last of the season, as it turned out, meaning these ticket-holders would have to find another way back. As in, buying another ticket from some other company.

The scandalous treatment of paying customers was first reported by Thrifty Traveler, whose main source was a married couple vacationing in Cancun, who thought their canceled return flight to Minneapolis-St. Paul meant they had no choice but to seek other accommodations. 

After 24 hours during which they were unable to reach Sun Country, the couple bought two one-way tickets for $600 a piece; only later did they learn that Sun Country was prepared to put them on another flight.

That wasn't the case for for Sun Country's passengers in Mazatlan and San Jose del Cabo. Thrifty Traveler quotes a message Sun Country sent to would-be passengers as ending this way: 

"You will receive a full refund. Flights will need to be purchased on another carrier. We apologize for any inconvenience this may cause." 

May cause? We can think of at least one inconvenience -- a monetary one -- getting a message like that would definitely cause. As Thrifty Traveler observes, last-minute one-ways from those Mexican cities to MSP Airport go for at least as much as that couple's flight back from Cancun, if not more.

City Pages -- which recently detailed Sun Country's incoming ownership group, long story short: the new guys are not pilots and flight attendants... or Minnesotans... oh, and they're thick as thieves with the Trump White House -- reached out to the airline for a response to these incidents of stranded customers.

Sun Country provided the following statement Sunday afternoon:

The April snow storm has absolutely slammed our MSP operations (and others—we understand there were 495 MSP cancellations yesterday); we had 25 cancellations yesterday and 15 today, plus five diversions and extensive delays due to the airport being closed for nine hours to all operations. The airport disruptions are continuing today; we hear there are 227 cancellations already.
Our agents are working around the clock, some of whom stayed past their shifts to work overnight in the call center, to provide the best service possible to our passengers impacted by all this. The two most challenging recovery situations are definitely our Los Cabos and Mazatlan flights. As soon as we realized we would be unable to re-accommodate these passengers we let them know of the situation and gave them a full airfare refund to make alternative arrangements. For all other flights, we are re-accommodating passengers to get them safely on their way as soon as possible.
An April snowstorm is an awful way to start or end a getaway and we apologize to everyone inconvenienced by the severe weather. We very much appreciate our customers’ patience and are doing everything we can to help them.