An ambulance speeds through Guatemala City with the 1986 American pop hit "Take My Breath Away" blasting on the radio. The unit is racing back to dispatch-and then another call comes in. An unidentified man has been shot in the head, execution style. The paramedics arrive on the scene and discover the victim's body face up on the sidewalk soaked in blood. Soon another ambulance will come to take the corpse to the morgue. Chances are the killer will never be found. A heroic army of mostly volunteer first responders comprises Guatemala's Bomberos Voluntarios, a saving grace in a city besieged by drug violence. This town of about 1.1 million, writes Zach Weissmueller is one of the most violent places on Earth because it's a central corridor of the drug trade; about 1 out of every 1,500 residents is murdered here annually. As the U.S. and Mexico pour new resources into fighting the drug war, the violence only gets worse. Government officials estimate that 95 percent of homicides in Guatemala City go unsolved.