Before we start, I want to make it clear this blog post is NOT about travel emergency medical insurance - that's a different topic.
In addition to the reasons I mentioned previously, there are a lot of reasons a trip can be interrupted such as jury duty, acts or threatened acts of terrorism, the provider of the tour fails to provide services (usually because of financial default).
Here are some things that actually happened on some of my trips:
Hurricane Sandy prevented travelers from getting a flight back to the U.S. Some were stranded overseas. Those who had trip interruption insurance were provided with hotels and travel services. If their trip had been interrupted on the outbound, in other words, the hurricane prevented them from getting to Europe, they would have been reimbursed for the trip.
In Peru, travelers lost their passports. Because of that, they had significant fees in getting an emergency replacement. They also missed a domestic flight while in Peru. Luckily, their insurance picked up the costs of getting the passport replaced and then got them back on the tour within 36 hours.
Trip interruption insurance is often available when you purchase your international airfare. However, I ran a quote from one company and found that for $114 at a trip cost of $3,000, you can get basic trip interruption insurance.