Their stories could fill a book. But each would only nick the surface of a crisis that is barreling toward us like a tsunami: We will soon have more intellectually and developmentally disabled adults living in this country than at any other time in our history.

Advances in medical care have allowed  kids born with Down syndrome,  for example, to live twice as long as they did just 20 years ago. And the explosion in the number of   children with autism  -- one in 68 children are now diagnosed -- means we'll soon have a vast population of adults in need of services like those Christina's family had hoped would keep her safe.

Add these numbers to those of children born with the two other most common roots of intellectual disability --  Fragile X syndrome  and  fetal alcohol spectrum disorder  -- and we have a looming social, economic, and moral crisis. What will we do about, with, and for these vulnerable adults and the families who struggle to care for them? And how much are we willing to pay for it?

What families have dealt with is shocking.