The fire was reported about 12:15 p.m. at a second-floor apartment in the 12100 block of South Indiana Avenue, according to Chicago police and fire officials.
Neighbors said the 13-year-old was alone in a bathroom when it happened. Neighbors said they saw him running down the hallway on fire, and that his clothes burned off. He ran outside to get help, where neighbors surrounded him and called 911.
"His brother was like, I just saw flames coming from under the door. That is when he opened the door and was screaming that he was on fire," said Larry Carthan, friend of the teen. "He was rolling on the ground so he could get the fire off him."
The boy was burned all over his body and taken to Comer Children's Hospital in critical condition, according to the fire department.
"His skin was all off and he was burning," Carthan said. "They wrapped him up and put the air breathing stuff on his face. His face was all pink."
His mother suffered burns to her arms and was taken to the University of Chicago Medical Center in fair to serious condition, authorities said.
Two other children, including an infant, were also taken to Comer in good condition to be treated for minor smoke inhalation, CFD spokesman Larry Merritt said. Additionally, a firefighter suffered an injury to his shoulder and was stabilized at a hospital.
Police said the fire may have burned through the unit's bathroom ceiling. Investigators have not yet said how the fire started, but suspect accelerants were involved.
"He kept telling his mom, 'I'm okay mom,'" said Carthan. "He was saying, 'I just hope that God doesn't let me die.'"
Neighbors said the fire could have been much worse because there are no working fire detectors in the building, and that they didn't even know there was a fire until they heard the screams.
"They need to be on their job, so what this is low income, this is something that helps people out, don't treat us like this," said Audreyanna Willis, upstairs neighbor. "Do better. This is your community, do better."
"No smoke detectors were activated," said Battalion Chief Perry Temple. "There are some in the building, but none were sounding when we got here."
Records obtained by the ABC7 I-Team show the building failed its most recent annual inspection in July of this year for violations related to the elevator. This inspection did not cite problems related to a fire or smoke detectors.
However, in September of 2018 the building was cited for "Smoke detectors - out of service (low batteries)" in the South Stairway and boiler room.
In all, the building has failed 13 different inspections since January of 2018 for problems related to the elevator and other violations like cockroaches, leaky ceilings and broken apartment doors.
ABC7 reached out to the Building Department for comment, and they said, "Our records show that the building was last inspected in November 2018 and was cited for building code violations that were written for an Administrative Hearings case. That case is still active. Prior to this, the building had been cited for violations earlier in 2018 resulting in an Administrative Hearings case and those violations were complied with."
The Sun-Times Media Wire contributed to this report.