Delta Air Lines passengers spent a day on the remote Azores island chain, nearly 1,000 miles from the European mainland.

According to the airline, an "indication of a mechanical issue in an engine" prompted the flight crew to divert the Airbus A330 to an Air Force base in the Azores. It is a remote chain of islands off the coast of Portugal. "Seeing all the emergency vehicles lining the runway, it reminded us it was a potentially dangerous situation," Elder said.