Some folks flying Spirit Airlines were out of luck this weekend when their flights were canceled or delayed, leaving them stuck at Fort Lauderdale-Hollywood International Airport.

Frustrated passengers blamed it on pilots who they said walked off the job. But a spokesman for Spirit Airlines was emphatic Sunday that there was no strike.

“Reports of a strike are completely untrue,” said Erik Hofmeyer, spokesman for the Miramar-based airline. “We have an incredible group of pilots who are working hard during this busy travel season.”

In all, 37 flights were canceled at Fort Lauderdale’s airport as of Sunday afternoon — and 34 of those were Spirit Airlines flights, according to the flight tracking website FlightAware.com.

Hofmeyer attributed the rush of cancellations to a “culmination of weather events and other operational challenges across various parts of our network. We are working directly with our guests to handle their needs.”

Hofmeyer declined to provide details on just what operational challenges the low-cost carrier is facing or how many flights had been canceled or delayed.

Passengers at Orlando International Airport were also stranded when their flights were canceled Saturday night.

Arlene Satchell, spokeswoman for Fort Lauderdale-Hollywood International Airport, didn’t offer many details, either.

“FLL is aware of some flight impacts today for Spirit Airlines and the airport operations team is assisting travelers where possible,” she said in a text. “Preliminary input from Spirit this morning indicated the flight impacts were not due to any pilot/crew strike action.”

Meanwhile, passengers vented on social media.

“There are no flights going out,” traveler Matilda Lucas tweeted Saturday night from Orlando’s airport.

Many were forced to rebook flights in Fort Lauderdale, too.

Bill Chambers had a flight to Philadelphia Saturday night that was delayed and then canceled.

“First they delayed it one hour, then it was delayed a second hour, and then it canceled on us,” Chambers told a reporter with WPLG-Ch. 10. “And it was a mad rush. It was like everybody ran for the ticket booths.”

Sandra Yepes was supposed to leave for Denver at 9 p.m. Saturday, but her plane never took off.

There could be a staffing shortage with gate agents and ramp crews, according to Suresh Atapattu, an editor for the industry website Airliners.net.

“I’m hearing they’re backed up because they have staffing issues with people loading and unloading the planes,” he said. “They just don’t have enough of them. The planes are piling up. And as the day goes on it gets worse and they cancel the flight. That’s what my sources at the airport are telling me.”

Atapattu said one pilot told him 30 flights were canceled on Saturday alone due to the staffing shortage.

If Spirit’s pilots had gone on strike, it wouldn’t have been the first time.

In 2010, the airline’s pilots went on a five-day strike after four years of negotiations failed to lead to a new contract. The walkout left thousands of passengers stranded nationwide.

In 2017, Spirit took a $45 million hit on its earnings due to an alleged work slowdown by the pilots that led to more than 850 flight cancellations. That included $25 million in lost revenue and $20 million in additional operating costs associated with re-booking passengers.

Susannah Bryan can be reached at sbryan@sunsentinel.com or on Twitter @Susannah_Bryan