A school assistant principal who was sick for several days with swine flu on Sunday became the city's first death linked to the virus. Mitchell Wiener, who had worked at an intermediate school in Queens, died Sunday evening, Flushing Hospital Medical Center spokesman Andrew Rubin said. Wiener had been sick for nearly a week before his school was closed on Thursday. He had been hospitalized and on a ventilator. Besides Wiener, no one else in New York City has become seriously ill from the virus. As of Sunday afternoon, health officials had reported five other deaths in the US: three in Texas, one in Washington state and one in Arizona. Internationally, at least 76 have died.