Shifting sands: Every year, about 120,000 Americans head south to Mexico during spring break season. Young college students, enjoying Mexico's drinking age of 18, engage in wild revelry and antics at beach resorts, as the youth above are doing in Mazatlán, in Sinaloa state, on March 18, 2001. The U.S. State Department, however, recently issued a travel alert, warning Americans about soaring drug-related violence in Mexico. Universities have even sent notices to students. Will the alerts scare U.S. citizens away, hurting Mexican resort operators' bottom lines?