Campaign aims to preserve more than 5,500 Titanic treasures

Ever since the Titanic sank to the bottom of the North Atlantic on a frigid April evening in 1912, the plight of the ill-fated ocean liner has captured the public imagination. Now, more than a century later, a campaign aims to preserve more than 5,500 treasures salvaged from the Titanic's watery grave.

A coalition of British museums, with the support of National Geographic and Oscar-winning filmmaker James Cameron, announced plans on Tuesday at the Titanic Belfast museum in Northern Ireland to raise $19.2 million to acquire the massive collection of artifacts, which is up for grabs. The money will support a bid submitted by the U.K.'s National Maritime Museum and National Museums Northern Ireland to buy the artifacts from Premier Exhibitions, a private U.S. company that holds salvage rights to the Titanic. 

National Geographic Society has become the first private donor, pledging $500,000 to support the bid.  

Since 1987, Premier Exhibitions, through its subsidiary RMS Titanic, Inc., has conducted eight research expeditions to the Titanic wreck site to recover shoes, dishes, eyeglasses, portholes and other Titanic artifacts. The collection has been viewed by more than 25 million people in exhibitions around the world.  

But the artifacts have faced an uncertain fate since Premier Exhibitions filed for bankruptcy in 2016. 

In addition to the British museums' bid, several other offers have been submitted to purchase the collection. At least one proposal calls for splitting up the collection and selling some of the artifacts off at auction.

That's something James Cameron -- a National Geographic Explorer-at-Large and the filmmaker behind the 1997 blockbuster Titanic -- doesn't want to see happen.

"If you ever visit the site you feel a deep responsibility," Cameron told CBS News. "You feel a responsibility to honor the dead, to honor the tragedy."

Since 1995, Cameron has made more than 33 dives to the Titanic's underwater resting place, spending more time on the ship than its captain did. He said that once Titanic is in your life, it doesn't leave easily.

"Securing the irreplaceable collection of artifacts, protecting and preserving them for future generations, by placing them in the public trust, is a unique and important opportunity to honor the 1,503 passengers and crew who died," he said.

Robert Ballard, a National Geographic Explorer and the oceanographer who discovered the Titanic wreck site in 1985, also supports the museums' bid.

The museums plan to co-own and conserve the Titanic's artifacts. The Titanic Belfast museum, built next to the shipyard where the Titanic was constructed, would display many of them.

The bankruptcy court may decide among the proposals to buy the Titanic collection at a July 25 hearing.