(CNN)A fire tore through a 2nd-story Chicago home overnight, killing six children, two adults and a dog, the city's fire commissioner said.
Chicago fire kills 8 people, including 6 kids, in a home with no smoke detector
"We have not had this in many, many, many years -- this amount of fatalities and injuries in one location," Commissioner José Santiago said Sunday morning.
But if not for the quick actions of a woman who smelled the fire, he said, the outcome could have been even more tragic.
The fire started on the 2nd floor of the building, Santiago said. The 1st floor of the building was vacant, and the 2nd floor was a home.
The relationships of those found on the 2nd floor was not immediately clear.
In addition to the eight people killed, two children were injured and hospitalized, the fire department said. A firefighter was hospitalized for overexertion and is in good condition.
Officials have not determined a cause of the fire. But public records show the building had two code violations during its most recent inspection in June.
One violation involved an "extension cord at rear exterior of fron [sic] building feeding rear Building (DANGEROUS AND HAZARDOUS," according to the city's building inspection records.
No smoke detectors were found in the charred home, the fire chief said.
The blaze also caused another structure to catch fire two buildings down, but no injuries were reported there.
Santiago lauded the quick thinking of a woman who "saved a lot of lives," in the neighborhood.
"She had just gotten home from work," the fire chief said. "She smelled it. I think she saw it. And then she started immediately knocking on doors, ringing doorbells."