On the same day rescue crews responded to an Elgin home on reports of an infant boy that was not breathing, someone contacted the Illinois Department of Children and Family Services' abuse hotline about the child's well-being, officials said Thursday.

Six-week-old Armando Ruiz died eight days after the calls were made, according to the Cook County medical examiner's office, and now his death is under investigation by police and DCFS.

Elgin Deputy Police Chief Jeff Swoboda said police and rescue crews were called at 1:17 p.m. Oct. 26 to a home in the to the 800 block of Van Street for a report of a baby that was not breathing.

The baby was taken to Provena St. Joseph Hospital in Elgin, then transferred to St. Alexius Medical Center in Hoffman Estates where he died Tuesday, Swoboda said.

Jimmie Whitelow, DCFS spokesman, said someone left an anonymous tip abut the child on the agency's hotline on Oct. 26.

"DCFS is investigating an allegation of abuse," Whitelow said Thursday.

He said the agency had no prior contact with the boy's family, and the infant was the only child in the home. He declined to answer any more questions.

A spokeswoman for the Cook County Medical Examiner's Office said an autopsy was performed Wednesday, but there will be additional investigation before the office issues a preliminary cause of death.

She referred further inquiries to a doctor, who was out of the office until next week.

Swoboda also declined to elaborate on the investigation.

"The police are investigating his death as is DCFS," Swoboda said.