One person was killed and two others were injured in a fire at a vacant building in the Logan Square neighborhood.
It happened in the 3400 block of West Armitage, just before midnight.
Officials say a mattress caught fire, and quickly spread.
The building was engulfed in smoke when firefighters arrived.
They pulled out a woman, who died and two men, who were injured.
The building has been vacant for six months, but officials say the three had been staying there for a while.