Eight people exposed to high levels of carbon monoxide at a construction site Monday have been sent to the University of Maryland's Shock Trauma Center for treatment.
Another three people were transported to local hospitals.
The incident unfolded Monday afternoon at a building under renovation at 14935B Southlawn Lane in Rockville. Several workers were exposed to high levels of carbon monoxide, according to tweets from Montgomery County Fire Department spokesman Pete Piringer.
Fire officials declared the rescue a mass casualty incident.
No additional information about the source of the carbon monoxide was immediately available.
Stay with News4 and NBC Washington for updates on this story.
