The Cook County medical examiner's office ruled Saturday that Donyvattia Kinermon, 37, was a homicide victim and said she died of ligature strangulation.
The woman's 5-year-old daughter, Sarah Farmer, and 4-year-old son, Chadrick Farmer, were found in an adjoining room that had filled with smoke and died shortly afterward at a hospital, said fire department spokeswoman Rosa Escareno. Autopsies on both were scheduled for Sunday.
Firefighters were alerted to the fire in the two-story apartment building on Chicago's South Side shortly after 11 p.m. Friday, Escareno said. She said the fire was confined to the bedroom where the woman was found and was incendiary in nature.
Chicago Police spokeswoman Patrice Harper said the Bomb and Arson squad was investigating to determine what or who started the blaze.
No one else living in the building was injured.
Kinermon had planned to have relatives bring the children's Christmas gifts to the apartment around midnight after the children were asleep _ trucks and puzzles for Chadrick, a doll and play dishes for Sarah, Kinermon's sister Deshon McDuffie told the Chicago Sun-Times.
Kinermon's mother lives in the same block, and her stepfather is pastor at a Baptist church a short walk away, she said. She described Kinermon as having ``an infectious laugh'' and said she loved R&B music. She rarely saw the children's father, McDuffie said.
``We don't know what could have happened, but we want to find out,'' said McDuffie's husband, Dan McDuffie.
Kinermon had four other daughters, the oldest now 19, who have been living with relatives since at least 1997 following investigations by the state Department of Children and Family Services, DCFS spokeswoman Diane Jackson said Saturday.
Jackson said six DCFS investigations in the past two decades had found cases of environmental neglect involving the family, such as a lack of working utilities in the home or other conditions that created an unsafe environment for children. The most recent investigation was in late 2003 but was closed after the mother made the required changes, Jackson said.
