Dozens of investigators have been in Pilsen throughout the morning trying to determine the cause of the fire. Five people suffered minor injuries and ten people have lost their homes.
Authorities say five residents were hospitalized for smoke inhalation after the three-alarm fire swept through three buildings. But firefighters say no one was seriously injured in the blaze because of the quick response from two brave Chicago police officers.
Chicago fire fighters got the call just after 1:30 a.m. Investigators say the fire started on the first floor and didn't take long to spread upstairs and to the buildings next door. Ten people were asleep when the fire broke out. Fortunately, two plain clothes Chicago police officers were on patrol nearby. They saw the fire, ran into the burning buildings and woke everyone up.
"I don't know what was going through my mind, I guess just making sure everyone was out and my partner was out," said Officer Michael Daliege, Chicago Police Department.
Firefighters were on the scene immediately and credit the police officers for acting quickly.
"The police were on the scene before us, they assisted in bringing people down from the upper floors. They actually assisted physically bringing people down," said Commissioner John Brooks, Chicago Fire Department.
Ramon Fragoso was asleep in one of the apartments upstairs. He says he is thankful to the officers for pounding on his door and getting him and his neighbors out safely. Two businesses - a bakery and a jewelry store - were destroyed. The family that owns Andrades Jewelry says they lost everything inside.
"Jewelry, clothes for kids, little knick-nacks for memories for communions, baptisms," said Lora Perez, business owner.
Some neighbors ABC7 spoke with Monday morning say they are suspicious about the cause of the fire, because they heard several big explosions.
"Like a big boom, boom and a big boom. I heard the squad car and could see where the police car was at and I looked up and I knew the back end of this building was engulfed from the floor all the way up," said Angel Maldona, neighbor.
The plain-clothed officers also alerted residents in neighboring buildings.
As the fire raged on, dozens of additional firefighters were called in to help battle the blaze, which spread to two neighboring buildings.
"We had to go to a defensive mode so we didn't go inside the building until right at the end because of a lot of structural damage," said Commissioner John Brooks, Chicago Fire Department.
The fire was struck out after several hours.
Firefighters say there were working smoke detectors in the building.
Two Chicago police officers were treated at the scene for smoke inhalation, and a third suffered a knee injury kicking in a door. A firefighter was slightly injured when he fell off a back porch. Everyone is expected to be OK.
The Chicago Police Bomb and Arson unit is in Pilsen investigating the cause.