A 21-year-old Long Island woman was fatally stabbed in her West Babylon home Saturday, authorities said.

A man suffering apparently self-inflicted stab wounds was also found in the home. He was expected to survive, cops said.

His relationship with the dead woman, Sonja Williams, was not known, but police say they have one child together.

Two children, 5 and 12 years old, who live in the house on Sheffield Avenue near Colonial Road, were not at home when the violence took place.