LONDON – A life jacket worn by a survivor of the Titanic is going on sale this weekend, in a rare auction described as a “once in a generation” opportunity. The jacket, which is expected to fetch between £250,000 ($339,000) and £350,000 ($474,000), is the only one from a survivor of the 1912 tragedy to go under the hammer, according to UK auction house Henry Aldridge and Son. The garment was worn by Laura Mabel Francatelli, a first class passenger on the historic liner, which sank 114 years ago this week. When RMS Titanic set sail on April 10, 1912, she was the largest passenger ship in service and considered to be “unsinkable.” Just four days later, the Titanic’s maiden voyage was transformed into an international tragedy when the ship struck an iceberg in the North Atlantic at 11:40 p.m. April 14. The ship, which sank in less than three hours, did not have enough lifeboats for the approximately 2,220 people on board. Only about 700 people survived. Francatelli was secretary to fashion designer Lucy Duff Gordon and was travelling to Chicago with her employer and employer’s husband, Cosmo Duff Gordon. All three survived after they managed to board life boat number one. Signed by Francatelli and others who were rescued in that life boat, the beige vest features 12 cork-filled pockets of canvas with shoulder rests and side straps, according to the listing on the auction house’s site. It is part of a wider auction of Titanic and White Star memorabilia to be held at Henry Aldridge and Son this weekend. Andrew Aldridge, managing director at the auction house, said it is “one of the most iconic” items ever to come up for sale from the ill-fated ship. 

“Quite simply this lifejacket presents a once in a generation opportunity for collectors, it’s the only example to ever be offered for auction from a Titanic survivor,” he said in an email to CNN Thursday.