An airline offering ultra-cheap flights from the U.S. to Europe suddenly shuts down

If you booked a WOW Air flight, you will have to change your plans. Iceland-based WOW Air suddenly grounded its flights, leaving passengers boarding a flight on Thursday stranded.

The airline posted a travel alert on its website on Thursday morning, telling passengers that "WOW AIR has ceased operations" and "all WOW AIR flights have been cancelled." All passengers holding WOW Air tickets are "advised to check available flights on other airlines," the alert said.

The announcement came without any warning, even for those planning a trip with WOW that day. The airline was still selling flights as late as Thursday morning, the BBC reported. Travel writer Victoria Walker even tweeted a screenshot of a WOW Air advertising email she received on Wednesday, the day before the airline folded. The company's collapse now leaves passengers stranded on both sides of the Atlantic.

As WOW's travel alert explains, only certain passengers can claim compensation or refunds. But for many people stranded in Iceland or elsewhere, or whose upcoming flights have been canceled, there is little they can do except book another flight.

“Stuck in Iceland because of #wowair,” one Twitter user wrote. “Does anyone have a private jet to take us out of here? Icelandair is already booked unless we pay $5000+…”

Other airlines are stepping up to help some passengers, though not in the form of free flights.

WOW's travel alert explains: "Depending on circumstances, some airlines may offer flights at lower prices, so-called rescue fares," but did not provide any specific details at the time. Wizz Air, easyJet and Norwegian all offer rescue fares, as the BBC later reported, adding that Norwegian is also offering a 25% booking discount to customers with a valid WOW Air booking.

However, this can still create a tricky situation for many passengers. WOW Air's trademark is low-cost transatlantic flights for passengers traveling between North America and Europe with a stop in Iceland. As Lonely Planet points out, for a last-minute transatlantic flight, or a last-minute one-way flight from Iceland to either side of the Atlantic, a 25% fare discount can still cost you a pretty penny.

Twitter basically erupted with angry complaints about WOW's sudden cancellation and poor customer service. Many people come from Iceland for vacation, and even under the best of circumstances, Iceland is an expensive country.

However, there have been some more emotionally fraught situations, such as a woman flying out to meet her husband and a family booking a WOW Air flight for March 31 to avoid overstaying their visa.

Lonely Planet advises stranded passengers to research compensation possibilities that may be available through a number of sources - their travel insurance or credit card company, or EU Passengers' Rights.

The Icelandic Transport Authority also provides information on its website. With its cheap flights, WOW seemed to offer a way to take the stress out of travel for millions of passengers, but now some of them are ending up in situations that are more stressful than ordinary travel.