Autopsies performed Monday on the bodies of a mother and her three sons found in a home in the Chatham neighborhood did not yield many answers.
The medical examiner identified the mother as 28-year-old Latoya Jackson, but the manner of her death is still pending further investigation.
The names and ages of the boys have not yet been officially released, and the manner of their deaths is pending additional tests, according to the medical examiner.
The bodies of the four were found Saturday evening at a home in the 8300 block of South Drexel, police said.
Police did not release any official information regarding the identities of the victims or the circumstances surrounding their deaths, but the grandfather of the three boys identified them Sunday as 11-year-old Andrew Simms, 9-year-old Cameron Jackson and 5-year-old Kentrell.
"I wake up this morning before I go to church, and I got here and heard the news. Shock, unbelievable," Leon Ervin, the grandfather, said.
It is unclear how long Jackson and her sons have been dead, however. Neighbor Donald Martin, who lives on the same block, told NBC Chicago he did not see the children playing outside at all last week, which is unusual.
Neighbors also said they noticed a potent smell coming from the home, and Martin called the police Saturday to alert them about it.
Area South detectives are conducting a death investigation to determine the circumstances surrounding the tragedy. Tom Ahern, with ATF, also said certified fire investigators were on the scene Sunday in the hopes of determining the cause and origin of a small fire that broke out in the house.
Family, friends and neighbors, meanwhile, have created a memorial in front of the home with balloons, flowers and candles.
"I've known Latoya ever since she was a little girl," one neighbor said. "She's a very caring mother, she loves her kids dearly, and it hurts my heart to hear that something tragic like this had to happen to her."