Christand Densmore, 5, was pronounced dead after being rushed to the hospital.
"He probably didn't want to leave his grandmother in there because she told all the rest of them to run out, run out the front door. I know he wouldn't leave her," said Tommy Porter, victim's uncle.
The late night fire also injured five others, including the boy's 70-year-old grandmother, who, according to relatives, is on life support.
"She mostly stayed inside, but sometimes when it got real hot, she would come sit on the porch and I would speak to her," said Renee Tigner, victim's neighbor.
The fire broke out around 11:30 Friday night. Firefighters arrived to find thick black smoke billowing from the two and a half story brick building as flames engulfed both the first-floor apartment where the victims lived and the second unit, which was vacant.
Tanya Sacks who was one of the first to call 911 for help shared what she saw.
"I saw them bring an older lady out. They began to administer CPR on her and one by one, they started bringing three lifeless kids out," said Sacks.
Seventy firefighters finally put out the flames after they spread throughout the building.
"We found that there were no working smoke detectors in the home. So if they would have had a smoke detector, they would have had an early warning of the fire and they didn't," said Deputy Chief Joe Roccasalva, Chicago Fire Department.
Christand died of smoke inhalation. Two other children were injured.
"It's hard to see the baby die," said Brian Washington, knew victim's family.
Fire investigators say it appears the fatal blaze began here in the back of the home. And although officials ruled out arson as a cause early saturday morning, its still unclear what sparked the fire.