Thomas Cook?

The oldest travel agency in the world has shut down, and quite suddenly.

Vacationers around the world are struggling to find a way home.  Future travelers have unpaid reservations.

Brexit may be one factor, but given that mess, I don't want to speculate how.  (That subject can compared to our own headaches in the states!)

I'd say it is the general decline for the need to use a travel agent when many vacationers can simply book air, hotel and car on the web. 

After all, the Bureau of Labor Statistics reports:

"Employment of travel agents is projected to decline 6 percent from 2018 to 2028. The ability of travelers to use the Internet to research vacations and book their own trips is expected to continue to suppress demand for travel agents. Job prospects should be best for travel agents who specialize in specific destinations or particular types of travelers."