Children wear surgical masks as they walk in downtown Mexico City April 30, 2009. Mexico began shutting down parts of its economy on Thursday to slow the spread of a new flu strain as officials urged increased worldwide precautions against an imminent pandemic. With its tourism industry savaged, shoppers staying home and exports to the U.S. in steep decline, Mexico could find itself in the longest, deepest recession it has seen in years, according to analysts. REUTERS/Eliana Aponte (MEXICO HEALTH)
REUTERS/ELIANA APONTE