Updated 01/26/11 – 3:05 p.m.

HAZEL CREST (CBS) — State authorities have launched an investigation into the death of a south suburban infant, in light of an allegation of neglect.

Five-month-old Doriano Washington was found unresponsive at his home on the 16700 block of Anthony Avenue in Hazel Crest on Tuesday. He was pronounced dead at 8:53 a.m. at Ingalls Memorial Hospital in Harvey, according to the Cook County Medical Examiner’s office.

An autopsy on Wednesday proved inconclusive, pending further studies, according to the medical examiner’s office.

The Illinois Department of Children and Family Services is investigating an allegation of neglect against the boy’s mother, spokesman Kendall Marlowe said. DCFS has had no prior contact with the family.

Two other children who were in the home have been placed in the care of relatives on Wednesday, Marlowe said.

Hazel Crest police also are investigating the death.

(The Sun-Times Media Wire contributed to this report.)