USA traveller Sean Tinschert said he rushed to the airport after he heard reports that the airline has ceased operating.
The carrier, which had been in funding talks with investors, flew from London Stansted and Gatwick in the UK.
For the passengers who had flights cancelled, WOW Air offers a number of solutions in that statement, though none of them are as easy as simply getting a refund on the cost of the ticket from WOW.
"She said it wouldn't happen and gave us a pizza, saying we're expecting a flight plan in the next 15 minutes", he told the BBC.
The Civil Aviation Authority said travel firms with an Atol licence are responsible for making alternative arrangements to bring their customers home if they are now overseas with a Wow Air booking.
Airlines including Wizz Air, Easyjet and Norwegian were offering flights, he added.
Other affected passengers also criticized Wow Air on social media over the lack of communication. Here, travelers wait in line at Iceland's global airport Thursday.
Wow's website suggests a range of possible methods of redress. Stefan Broddi Gudjonsson, an economist at Arion Banki, said the Wow Air debacle could cause tourist numbers to drop by around 16 per cent in 2019.
Wow was founded in 2011 by its chief executive, Skuli Mogensen. The company announced that the flight schedule would continue as normal while an emergency meeting with its shareholders was being set as the last resource for the company to receive capital, but at 9 a.m. local time all hope was lost: all planes were instructed to be grounded.
WOW air said that 2018 was a "challenging year".
Rory Boland, the travel editor of Which?, said Wow had been selling flights right up until 07:00 on Thursday morning.
Passengers should also consider making a claim with their travel insurers. For instance, Chase Sapphire-branded credit cards cover "financial insolvency of the Travel Agency, Tour Operator, or Travel Supplier whose services you booked" under its included travel insurance as long as you purchased the flight using your Sapphire card or Chase Ultimate Rewards® points.
The Icelandic Transport Authority has posted information for Wow customers in the wake of the sudden news that the airline had shut down.
In its early years the airline expanded fast to 37 destinations and reported up to 60 percent annual growth in passenger numbers.
"Customers who have booked their tickets directly with the airline do unfortunately have narrow chances of reimbursement of their costs and must address their claims directly to the bankruptcy trustee of the airline", confirms Henrik Zillmer, CEO of AirHelp.