Three children and 16 adults were displaced because of a carbon monoxide leak early Tuesday in a building in the Gage Park neighborhood on the Southwest Side.
Firefighters responded about 12:30 a.m. to a Level 1 HazMat situation at 5805 South Sacramento Avenue, according to Chicago Fire Media Affairs.
The cause of the situation was a high carbon monoxide reading caused by a faulty boiler, officials said.
No injuries were reported. A warming bus was called for the displaced residents until the situation was resolved by about 12:43 a.m.
