In his first interview since the tragic shootings at the Safeway in Tucson, Arizona, Capt. Mark Kelly sits down one-on-one with Diane Sawyer to offer an intimate portrait of a modern American love story, and to talk about a great national tragedy and finding the strength to heal. Their emotional conversation took place one week after the tragic shooting.

They started out like any kids, full of hope and dreams - but now they're homeless and in terrible danger of slipping between the cracks. These kids are not living under a bridge, but under the radar -- part of a new under-reported type of homelessness -- surfing from couch to couch, from the beds of friends to the beds of strangers. For over a year, Chris Cuomo and his team have chronicled the terrors and triumphs of four such teenagers, all surviving largely on their own.