There's a cluster of neural tube defects happening to babies in Yakima, and no one can figure out what's going on.

Federal and state officials won’t say how many women in a three-county area near Yakima, Wash., have had babies with anencephaly, a heart-breaking condition in which they’re born missing parts of the brain or skull. And they admit they haven't interviewed any of the women in question, or told the mothers there's a potentially widespread problem.

But as of January 2013, officials with the Washington state health department and the Centers for Disease Control and Prevention had counted nearly two dozen cases in three years, a rate four times the national average.

HuuuWHAT?

They examined where the women worked, what diseases they had, whether they smoked or drank alcohol, what kind of medications they took and other factors. They looked at where they lived and whether they got their water from a public source or a private well. They looked at race and whether the problem was more pronounced in the area's migrant farm workers or in other residents.

In the end, there was nothing — “no common exposures, conditions or causes,” state officials said — to explain the spike.