A fire that followed the explosion ignited just after 6:30 a.m. in the 6600 block of South Keating, just blocks away from Midway Airport. Some neighboring homes also caught fire, and several were injured in the incident, including a firefighter.
Investigators are looking into whether a natural gas leak led to the blast.
The couple who occupied the now flattened split-level brick home in the West Lawn neighborhood managed to escaped. Witnesses say Ana Oyola, 46, suffered cuts and heat exhaustion, and her husband Pedro Sepulveda, 61, was severely burned. The couple's son was not injured since he was just getting home as the house exploded.
Neighbor Rudy Venegas' home security camera caught some of chaos during the explosion. While he ran to the get an older woman out of one of the neighboring homes, Venegas saw Sepulveda stumble out of the rubble that was once his home.
"I seen him walking around the side. He was on fire," said witness Rudy Venegas.
Next-door neighbor Doreetha Wheatley was awakened by the blast, then saw fire spread to her home. She, her husband, and four kids escaped the flames through a front window.
"It's unbelievable. We didn't know what happened. It was just this loud explosion. The smoke filled the entire block," Wheatley said.
It took some time for over 250 firefighters to get the situation under control.
"It was bang after bang. It was like explosion after explosion. The fire was just coming up, up and up and up," said Melba Serrano, who was visiting the neighborhood.
"There was no visibility in the street for a block or two north of this incident. So you had a lot of fire, a lot of smoke, a lot of wind pushing through the neighborhood," said Chicago Fire Department District Chief Peter VanDorpe.
Some on the block say they noticed the odor of natural gas just about the time the owner of the house that exploded started some construction work in his basement.
Peoples Gas temporarily shut off service to the dozens of residences on the west side of Keating. As crews took gas readings at every home in that area, officials searched for what sparked the explosion.
"We don't know the cause or the source, and we're working with all the agencies on site as we continue our investigation. It's going to be an on-going investigation," said Bonnie Johnson, spokeswoman with Peoples Gas.
On Sunday night, Sepulveda remained in the Stroger Hospital Burn Unit in stable condition. ABC7 was unable to confirm where Oyola was hospitalized.