Police say carbon monoxide poisoning is to blame for the deaths of a Middletown doctor, his wife and a houseguest.

According to authorities, Dr. Laurence Spiro, his wife and their houseguest were found dead Monday at the doctor?s home in Rock Hill. Spiro was a urologist practicing at Orange Regional Medical Center. His colleagues became alarmed when Spiro did not show up for surgery Monday.

Officials believe the three died while sleeping, a time when most people cannot feel the effects of the poisonous gas. Fire officials say only a detector will pick up the presence of carbon monoxide.

Related linkCarbon Monoxide Network