As we feared (and reported last December) the discount airline WOW suddenly ended service this week, stranding thousands of paid passengers. Fortunately, this is a very rare occurrence in travel, and there are often warning signs in advance (as we noted last December).
How can travelers protect themselves? Travel insurance. There are many reasons to buy travel insurance and this is one. Buying a policy that reimburses you in the event the travel supplier discontinues services may be the only way to get your money back. In addition, most carriers (and your travel agent) will help you with your disrupted travel.