DC Fire EMS: high levels of CO inside of 3-story boarding house on the 500 block of U St NW

See this tweet:

CO incident 500 Blk. U St. NW. 8 occupants of 3 story boarding house tx to hospitals after we found high levels of CO inside. None life threatening. Source traced to furnace. We urge all citizens to have working CO alarms at home & know CO symptoms. #DCsBravest. pic.twitter.com/M7iUeDeNvX

— DC Fire and EMS (@dcfireems) November 12, 2017