will not go away. and tom fallis and his children make a life as best they can. >> that's all for this edition of "dateline." i'm craig melvin. thank you for watching.can. >> that's all for this edition of dateline. i'm craig melvin. thanks for watching. i'm craig melvin. >> and i'm natalie morales. >> and this is dateline. >> this doesn't happen in our happy little world. >> their world shattered, a young mother strangled. >> we had a homicide and no suspects. >> also no evidence. but police found a dark side behind that bright suburban facade. >> she slept with the children and the door locked. >> and finally a vital clue. what happened to nancy the day she