The wreckage of the Pan American Airways Clipper Endeavor has been located 74 years after it crashed off the coast of Puerto Rico, in a discovery credited with prompting the aviation safety measures still used on flights today. The aircraft, which suffered multiple engine failures shortly after take-off on 11 April 1952, was forced into a violent water landing; passengers' difficulty finding life vests and rafts as the plane rapidly sank became a catalyst for reforms including the mandatory pre-flight safety briefings now standard on every commercial flight.

The Douglas DC-4 was found roughly 2,000ft below sea level using a sonar-equipped drone, in an expedition led by the Air/Sea Heritage Foundation alongside the Discovery Channel's Expedition Unknown and other partners. Of the 69 passengers and crew aboard when the plane went down while flying to New York, only 17 survived. Foundation president Russ Matthews began investigating the crash in 2019 after learning of a luggage tag from the flight washed up in Florida, and used historical records, weather data and witness maps to narrow the search area, finally locating the broken wreckage – with the Pan Am logo still visible – on 2 June, ahead of the crash's 75th anniversary.