Investigators are now looking into whether children playing with fireworks might be to blame.
The fire broke out around 10 a.m. Saturday morning. It also spread to neighboring residences in the 1500-block of West 17th Street.. Multiple Chicago Fire Department units were called to the scene to help contain the fire.
Close to two-dozen people were displaced as a result of this fire that destroyed one apartment building and seriously damaged two others.
As work crews worked to demolish what was left of the building where the fire started, investigators are still looking into a cause of the blaze-- some residents say they heard children playing with fireworks in the back of the building before the fire started.
Calls for help first began just before 10 a.m. as the neighborhood enjoyed the start of the Fourth of July holiday weekend.
With nothing more than her purse, a childhood doll and the clothes on her back, Veronica Barrios fled the fast moving fire.
"There's no words to describe it," Barrios said.
Firefighters arrived to find, not only the three-story Pilsen apartment building engulfed in flames, but also fire spreading to residences on both sides.
"My friend came banging on the door, talking about, 'Get out—its' fire.' I looked out the window, the whole house next door's just burning down in flames," said Larry Mayfield, fire victim.
A 14-year-old boy was cut on the leg as rescuers helped him to escape the flames through a broken first floor window. But everyone else managed to get out of the burning buildings unharmed, including Hector Saldana, who tried to be positive about his misfortune.
"I have a trip to New York on Wednesday," said Saldana. "I'm thinking, I don't have to pack much now, but I'm glad I'm out and the dogs are ok."
Meanwhile, resident Elie Richardson admits she's in denial. She returned from the laundromat to find her basement unit in flames and her cat, Cleo, missing.
"That's kind of what I'm waiting just to hear-- if they've been able to find her, if she got out, mainly," said Richardson.
Fire officials are still investigating a cause.
Some neighbors say they heard children playing with fireworks in the building's gangway shortly before the fire broke out.
"This time of year, who knows for sure. I would be wrong to make a statement," said Deputy Commissioner Gene Ryan, Chicago Fire Department.
But, for some, the fire's aftermath is almost too much to deal with.
"It's just gone," said fire victim Jose Arauz. "Everything's gone. Great. I'll have to start all over."
The demolition began around 4 p.m., after the city's Buildings Department came through to determine that the building was no longer viable. Crews worked into the late afternoon to try to make it safe for neighborhood residents in the area.
One of the neighboring buildings had already survived a fire and was under renovations when this fire began. There are some damages to the back of that building. The other building damaged by the blaze was fully occupied. There is serious damage to the back of that building.
Fire officials say one firefighter was slightly injured when he slipped and lost his footing.