Wreckage of Pan Am plane found 74 years after it crashed off Puerto Rico

A mosaic image of the Clipper Endeavor wreck is pictured. (Courtesy of Air Sea Heritage Foundation and Deep Sea Vision via CNN Newsource)

Seventy-four years after a Pan Am flight crashed into the water off Puerto Rico, killing 52 people and prompting sweeping reforms including preflight passenger safety briefings, an aviation search team has found the wreckage sitting on the ocean floor.

The Air/Sea Heritage Foundation, in partnership with others including the Discovery Channel’s “Expedition Unknown” show, last month found the wreckage of the Pan Am “Clipper Endeavor” at the bottom of the Atlantic Ocean off Puerto Rico’s northern coast, Discovery said in a release Tuesday.

The discovery, which involved an autonomous underwater drone, ends decades of mystery about precisely where the Douglas DC-4 aircraft came to rest after crashing into the ocean shortly after it took off from Puerto Rico on April 11, 1952, with 64 passengers and five crew members aboard.

Although all passengers survived the initial impact, only 17 people would be rescued, and the rest would be lost with the quickly sinking plane – a result that investigators would blame in part on a lack of safety briefings and that would spur changes in the aviation industry.

“We are all stunned and elated by this discovery yet also humbled to remember what happened in that place so long ago,” Russ Matthews, president and co-founder of the Air/Sea Heritage Foundation, said in the release.

NBC first reported the discovery on the “Today” show Tuesday morning.

The search team, which also involved the Deep Sea Vision company, used high-resolution sonar to locate the wreckage on the ocean floor some 2,000 feet below the surface on June 2, the release said.

By chance, a research vessel with one of the world’s most leading-edge sonar systems had passed right through the team’s narrowed search zone and agreed to stop for 48 hours to help with the search.

“It went down for about 30 hours and scanned the sea floor in our target area, came back to the surface, and there it was,” said Josh Gates, a host of Discovery Channel’s “Expedition Unknown.”

The craft was broken into two sections. A follow-up photographic survey conclusively identified the plane, with images clearly showing the iconic winged Pan American logo and aircraft name still legible, according to Discovery’s release.

Discovery Channel intends to cover the finding in an “Expedition Unknown” episode later this year. Discovery Channel, like CNN, is owned by Warner Bros. Discovery.

The Air/Sea Heritage Foundation is now working with the government of Puerto Rico to expand protections for the wreckage site and is advocating for a memorial honoring those lost in the crash, according to the release.

Families directly impacted by the tragedy and the crash’s only two known living survivors have also been contacted, the release said.

Crash led to aviation changes

The plane, which was bound for New York, lost both right-side engines shortly after takeoff, according to the Pan Am Historical Foundation, forcing the pilot to conduct a violent water landing minutes later.

The aircraft had life rafts and personal flotation devices for all aboard, according to the Pan Am foundation. But confusion ensued in part because no safety briefing was given, there was a language barrier, and no coordinated evacuation procedure was in place, Discovery said in its release. The plane sank in less than three minutes, Discovery said.

Though the U.S. Coast Guard and Air Force sprang into action to save 12 passengers and five crew members, Discovery said, the other 52 people aboard died.

The two known survivors still alive today are a woman, now 102 years old, who was a nurse in her 20s and instrumental in opening the aircraft door to let passengers out, and a baby, found floating on the surface of the water, who was resuscitated by rescuers, according to Gates. Both were very emotional and gratified when they were told that wreck had finally been found, Gates told CNN’s Boris Sanchez.

In a report on the 1952 crash, the Civil Aeronautics Board, a predecessor of today’s Federal Aviation Administration, proposed amendments to the civil air regulations “to assure a greater degree of safety to the occupants of aircraft flying over water routes.”

Proposals that were implemented included preflight briefings for passengers on where to find and how to use life vests, life rafts and emergency exits.

“Having had the cabin crew establish their authoritative position before a flight would make both their task and their message more effective when it mattered most,” Doug Miller, with the Pan Am Historical Foundation, told CNN. “Eyewitness accounts of the tragedy indicated that the passengers refused to understand the gravity of their situation, despite what they were hearing from the crew.”

“Every time you step onboard an airplane today, you are safer because of what happened to ‘Clipper Endeavor’ and her passengers three quarters of a century ago,” Gates said in the company’s release.

Rebekah Riess, CNN