Hotel deaths highlight often undetected killer

It seemed, at first, like a mystery: Why did three people - an elderly couple and then, two months later, an 11-year-old boy - die in the same North Carolina hotel room? In the absence of obvious evidence, some Internet commenters blamed "the spooky side of things" and raised the specter of a "haunted" hotel in the immediate aftermath of the third death. The reality, officials later revealed, was nothing so fantastical: The victims had been exposed to elevated levels of carbon monoxide, an odorless, colorless gas that results in hundreds of accidental deaths in the United States every year, according to the Centers for Disease Control and Prevention.