Wilkanowski was also known to be a family man, doting on his wife Amelia (1886 – May 6, 1952), with whom he had raised 9 surviving children. When Amelia got sick, in 1950 he moved his workshop to their Long Island home to be close to her and look after her. After she died of the illness in 1952, he became very depressed and despondent without her. William stopped making instruments altogether and lost his source of income, which negatively affected his finances, adding to his depressive state. In early December 1954, he finally committed suicide and was laid to rest next to Amelia on December 13, 1954.