Searchers have located the wreckage of a Pan Am flight that crashed into the sea off Puerto Rico in 1952, killing 52 people and inadvertently becoming the reason you have to watch a flight attendant point at an exit door before every takeoff.

The Clipper Endeavor went down when two engines failed shortly after takeoff. The 17 survivors all made it through the splashdown, but then panic set in as passengers fumbled for life vests and crew struggled with life rafts. Within minutes, the plane sank. Thirty-nine bodies were never recovered.

Explorers found the DC-4 in June when a robotic sonar drone located the fuselage and tail in 600 metres of water. Aviation safety expert John Cox called the crash a "catalyst" that drove safety reforms like better flotation equipment and those preflight briefings we all pretend to pay attention to.

The disaster led to sweeping changes; today, flight attendants instruct passengers on exit locations and life vest inflation - a ritual most people ignore while scrolling through their phones.

In 2019, Russ Matthews of the Air/Sea Heritage Foundation saw an article about a luggage tag from the flight washing ashore in Florida. That kicked off years of digging through Pan Am and Coast Guard archives, plus Civil Aeronautics Board reports. The key turned out to be a map from a Puerto Rico hearing, drawn by Air Force pilots who witnessed the crash.

Tony Romeo, CEO of Deep Sea Vision, joined the effort when one of his ships happened to be in the area with an advanced underwater drone. His firm previously led an unsuccessful six-month search for Amelia Earhart’s plane. Matthews’ group combined research with weather data to produce a search map covering 10 square nautical miles. The drone found the wreckage on its first pass - no six-month ordeal this time.

The discovery could offer hope to families of those lost in ocean crashes like flight MH370, the Malaysia Airlines jet that disappeared 12 years ago with 269 people on board. The search will be featured on an upcoming episode of Discovery Channel’s Expedition Unknown.