Add Us On Google Add as a preferred source on Google ST. LOUIS, Mo. (First Alert 4) - A carbon monoxide leak Friday morning in a Phelps County duplex has killed five and injured two. According to the Phelps County Sheriff's Department, first responders went to the duplex just before 5:30 a.m. for a carbon monoxide alert. The duplex is just east of Rolla, according to the department. When first responders arrived, they found five people dead, one person with moderate injuries and one person critically injured. While first responders were removing victims from the duplex, a deputy was exposed to carbon monoxide and was treated by EMS. The identities of the victims have not yet been released as the sheriff's office is working to inform their families. The department says they are investigating to determine the circumstances of this incident. Our thoughts and prayers are with the injured individuals and the families of the deceased, a statement from the department said in part. We extend our heartfelt condolences to those affected when their identities are confirmed. Further updates will be provided as more information becomes available. #firstalert4 #crimewatchstlouis