A school assistant principal who was sick for several days with swine flu on May 17 became the city’s first death linked to the virus and the nation’s sixth.

Mitchell Wiener, who worked at an intermediate school in Queens, died the evening of May 17, Flushing Hospital Medical Center spokesman Andrew Rubin said. Wiener, who had been hospitalized and on a ventilator, had been sick with the virus for nearly a week before his school was closed on May 14. Complications besides the virus likely played a part in his death, Rubin said.

Mayor Michael Bloomberg said the death of Wiener, who was 55 and had taught for decades, “is a loss for our schools and our city.”

“He was a well-liked and devoted educator,” Bloomberg said in a statement.

Wiener was hired as a substitute teacher in March 1978, then as a mathematics teacher, working in that position until 2007. Since then, Wiener had been employed as an assistant principal at I.S. 238, also known as the Susan B. Anthony Intermediate School, in the Hollis neighborhood.

Besides Wiener, no one else in New York City has become seriously ill from the virus. As of May 17, health officials had reported five other deaths in the U.S.: three in Texas, one in Washington state and one in Arizona.

Most people sickened from the swine flu, or the H1N1 virus, have complained of mild, seasonal flu-like symptoms such as fever, cough, sore throat, body aches and fatigue.

The city’s first outbreak of swine flu occurred three weeks ago, when about 700 students and 300 other people associated with a Catholic high school in Queens began falling ill following the return of several students from vacations in Mexico, the epicenter of the outbreak. The school was closed.

Five more city schools were to close May 18 because of concern for swine flu, bringing the total to 11, including Wiener’s.

City health officials announced that four Queens public schools and one Catholic school would close for up to five school days. Three of the public schools are in the same building in Flushing. Each school had students with flu-like illness last week.

The latest school closings will affect nearly 3,000 students. Schools will be providing curriculum material online, and parents will be able to pick up materials at schools and other locations, schools Chancellor Joel Klein said.

There were no documented cases of swine flu at any of the schools, said Jessica Scaperotti, a spokeswoman for the city’s Department of Health and Mental Hygiene.