(NEWSER) - Schools and museums are closed, sold-out soccer games are being played in empty stadiums, and health workers are ordering sickly passengers off subways and buses. At nightclubs, teenagers are dancing with surgical masks on. Mexico City is grappling with what authorities fear is ground zero for a global epidemic of a new kind of flu—a strange mix of human, pig, and bird viruses that appears to have killed 68 people and has sickened more than 1,000. More»