They are standing in front of something that looks like a puzzle made of pieces of twisted metal, and that is why there are no smiles. Because they know that it isn't a puzzle. It is a 1990 Buick Riviera in which a woman and two little children died. And they died because someone drank too much, got behind the wheel of a truck and killed them. They are not smiling because they know that, for the owners of that car, there is no more family.
Mom is dead.
The babies are dead. There will be no joyous Christmas mornings, no family dinners, no chance to watch grandpa teach the little ones how to catch a fish, or build a birdhouse. Grandma won't be making any quilts to pass on to the family she loves, or kissing scraped knees to make them better. And the little children, those fragile, precious bits of flesh molded by the hand of God, are now in their graves, until the end of time. P.S. - I just noticed that grandma is smiling a little.