Each of the dead shared his father's name. And over the last seven months, the boys' deaths have linked three more families in the deepest most unforgiving way -- one that they have been too devastated to speak about, until now.

Special Report: Oakland child killings  

In 2010, Oakland had more than 500 separate shootings -- more than one per day, every day, for weeks and months on end. Some involved so deeply in street life that experts say they have slipped into a kind of alternate reality in which the rules the rest of society lives by don't apply  

They call it "psychological first-aid" — triage for the emotional wounds inflicted by the violent death of a student, a friend, a relative, a classmate. In Oakland schools, it is needed all too often. Eight of the city's 2009 homicide victims were teenagers who were enrolled, or recently enrolled, in Oakland public schools.  

It's hard to put a price on death. But 124 times in Oakland last year, homicides forced someone to perform this perverse calculation. Tragic circumstances can compel individuals, neighborhoods and cities to put a dollar amount on the cost of killing.