Montgomery County, MD – Several people were evaluated for carbon monoxide poisoning late Wednesday evening in Gaithersburg, Md., authorities said.

Officials say, shortly after 11 p.m. first responders were called to a home located at 18700 Barn Swallow Terrace.

A generator in an unventilated area of the home had created high levels of carbon monoxide, Pete Pringer, a spokesperson for Montgomery County Fire and Rescue Service tweeted.

By late Thursday morning there was still no word on the condition of the victims.