Teachers' union officials say that 40 city schools have high numbers of absent students today, as a Queens middle school mourns its assistant principal who is the first fatality in the city's H1N1 flu outbreak.

St. David's, a private boys school on Manhattan's Upper East Side, has closed for the day after many students reported flu-like symptoms.

United Federation of Teachers officials say they are monitoring 40 city schools with high student absentee rates to determine more school closings, while keeping panic and misinformation to a minimum.

Meanwhile, a spokesperson for Flushing Hospital Medical Center said Assistant Principal Mitchell Wiener of I.S. 238 in Hollis, Queens passed away yesterday evening.

Wiener, 55, had been hospitalized since Wednesday, and suffered from an underlying medical condition, according to Outgoing City Health Commissioner Thomas Frieden.

Wiener's family said that the assistant principal had been taking high blood pressure medication and had been treated in the past for gout. During his hospitalization, he was on a ventilator and suffered from kidney failure and a lung infection.

Weiner's widow Bonnie, who is a teacher at the same school, blamed the city for not acting sooner to close the school.

Four other students at I.S. 238 have been confirmed to have the virus.

Mary Megaerditch, the wife of a man in a neighboring room at Flushing Hospital, said she offered comfort for the family when Wiener died.

"I heard the all the doctors to the [intensive care unit], I know something happened," she said. "When I went out, [Bonnie Wiener] said, 'My husband died and she was hugging me and I was hugging her."

Mayor Michael Bloomberg said today that Wiener made a valuable contribution to the Queens middle school.

"Mr. Wiener was a dedicated educator. He was well liked by his students and he cared deeply about them, and his death really is a tragedy for our city and a terrible loss for the school community at I.S. 238," said the mayor.

Of the 12 schools currently closed, the only confirmed cases of H1N1 have been from I.S. 238.

Schools Chancellor Joel Klein said today he was not concerned about schools needing to make up lost days in the summer or city schools about losing federal school aid.

"If your kid has a fever, keep your kid home. You don't have to do any grievances," said Klein. "Teachers who are not feeling well, stay home - this is not a time for us to worry about grievances. We got to worry first and foremost about the safety of our students and our staff."

UFT staff said that schools' absentee rates could be driven up by students afraid to go to school, and teachers' union President Randi Weingarten said that her officials have set up hotlines to keep track of school absences.

"My staff is monitoring every single school in which we see a lot of kids getting sick, in which we see a drop in attendance and where we see come confirmed cases," said Weingarten. "And literally every five minutes, my staff is giving that information to the [schools] chancellor's staff and to the DOH staff."

Department of Health officials say decisions to close schools are being made on a case-by-case basis.

City health officials have stressed that most cases of H1N1 flu have been no more several than seasonal flu. People who are have compromised immune systems or have severe symptoms should seek medical help.

Meanwhile, the H1N1 epidemic is dominating the World Health Organization's five-day annual meeting, now underway in Geneva.

The organization are examining transmission rates and hearing experts' recommendations on producing a vaccine.

Dr. Margaret Chan of WHO said the swine flu epidemic is in a "grace period" with the threat alert remaining at a phase 5 of 6.

The group is also monitoring outbreaks in Japan, Britain and Spain.

Japan's total of confirmed cases has climbed to 130. Most are teenagers, prompting the government to close 2,000 schools and cancel public events.

The H1N1 flu virus has infected almost 9,000 people in 40 countries and is to blame for at least 76 deaths.

Regular flu kills about 36,000 people in the United States each year.