Postcard from Culiacán

In the predawn hours of Sunday morning, a ringing phone in the Red Cross base in this violence-torn Mexican city is a warning of impending tragedy. The first responders on call on this particular night had already seen plenty of action: a man with a bullet embedded in his skull; a beaten corpse dumped on a street corner; a blood-soaked drunk who tried to pull a policeman's gun from his holster. But the worst had been waiting until last. Someone was calling in from the middle of a firefight raging in a rough neighborhood on the outskirts of town. Several men...