Indiana Township, PA – More than 20 people reported feeling ill at a group home in Indiana Township and about a dozen were treated at local hospitals.

Initial reports indicated the patients may have been overcome by carbon monoxide.

Post-Gazette news partner KDKA-TV said 11 people were transported from the facility on Challenge Lane shortly after 8 p.m.

The facility is known as Western PA Adult & Teen Challenge, an addiction treatment center. The residents returned to the facility Friday, KDKA reported.