Wiljo Unto Johannes Hämäläinen was born on 4 February 1911 in Merrimac, Essex, Massachusetts. He was the son of John, a metal beater, and Anna Lydia Amanda (nee Wartianen) Hämäläinen.
Anna and Wiljo were rescued (in which lifeboat is not known).
He died 18 March 1914 in Detroit, aged 3, listed as William Hamlin. One of the first Titanic survivors to die. The cause of death was given as endocarditis. He was buried four days later at Gethsemane Cemetery in Detroit.