An original Titanic launch ticket, currently valued at between $50,000 and $70,000, is among a series of Titanic-related items set to be auctioned off on April 15 by Bonhams auction house in New York. Also included in the lots are letters from survivors and memorabilia from the 1953 and 1997 films; the auction will commemorate the 100 th anniversary of the ship's sinking after it hit an iceberg only four days into its maiden voyage.

According to the Bonhams  website, the ticket, which has the perforated admission stub still attached, is the only known one of its kind. Had it been used, it would have granted the bearer admission to the ship's May 11, 1911, launch. Launched before it was fully equipped as a luxury liner, the Titanic was never christened, as per the policy of its operator, the White Star Line, a fact some attribute to the ship's ill fate.

Another star lot is an account of the R.M.S. Carpathia's rescue account of Titanic survivors, written by that ship's captain, Arthur Henry Rostron. The account is projected to sell for anywhere between $90,000 and $120,000.

The supposedly unsinkable ship hit an iceberg on the night of April 14 , sinking to the bottom of the ocean by the next morning. More than 2,000  people were aboard the luxury liner; 1,503 died in the incident, mostly from hypothermia. The wreckage of the ship, images of which can be seen here, wasn't found until 1985.

For more rare Titanic memorabilia set to hit the auction block, check out our slideshow here.