A Delta jet experienced engine problems on what was supposed to be a trans-Atlantic flight and landed on an island in the middle of the ocean, leading to a more than 31-hour delay, officials said Thursday.

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.