Police and firefighters responded to 27 Coyle Place just before 8:30 a.m. after a man returned home and said he could not wake his family.
First responders found 11 individuals ranging in age from 1 to 40 who appeared to be suffering from various degrees of carbon monoxide poisoning.
Initial readings found CO levels above 1,000 parts per million. Experts say symptoms can begin at any level above 70 parts per million.
Martha Gomez lives across the street was holding a young child at the scene.
"I grabbed the baby from him and then he started to vomit," she said through a translator.
The victims, six children and five adults, were removed to local area hospitals and trauma centers and are expected to survive.
They were said to be conscious as they were being evaluated, but some of them were vomiting and had red complexions.
The building was evacuated, with no other injuries reported.
City and Utility Service inspectors were called in to investigate.
The cause is under investigation but believed to be faulty heating equipment.
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