The Titanic is famous because of the hubris involved; it was the biggest, fastest, most luxurious ocean liner ever, that sunk basically just because its captain was trying for the Blue Riband on its maiden voyage (also, a lot of rich and famous people died). The Lusitania is famous because it was a hospital ship attacked during wartime and was used to drum up support for allies entering the war (it was a major factor in the US entering).
For whatever reason we don't really care about normal civilians dying en masse during peacetime accidents. So many people died in the General Slocum disaster that it wiped out the Little Germany neighborhood of New York: