Two people, including one who jumped from a window on the second floor, were taken to the hospital. The complex is located on Wabash St.
Kevin Carpenter woke up to the fire around 3 a.m. The complex is located next door to him.
"You didn't really even see the blaze, just a lot of smoke coming out the side," Carpenter said.
His good friend, who is the mother of five, lives on the second floor of the building. She had to jump out of a small window to escape her smoke filled unit.
The woman landed hard, fracturing her spine. She was released from the hospital and his recovering.
The Red Cross placed her and six other families in a hotel for the next three days.
Investigators are still trying to determine a cause. It was contained to the first floor unit in the back of the building, but the other units have smoke and water damage.
Residents say Saturday's fire wasn't the first. There have been several in the past year.
They say the units are old and suspect at least in some of the cases, frayed electric wires are to blame.