On Wednesday, a 12-year-old middle school student in Queens hanged herself, leaving behind a note saying she had been harassed by classmates at school and bullied online. What can be done to prevent tragedies in the future? One issue may be that teachers are unaware when students are being bullied, especially when there is cyber-bullying. According to the Learning Environment Survey at IS 109, the school Gabrielle Molina attended, 80 percent of the students said there was bullying; but only 15 percent of teachers said students were bullied.

About 30 percent of IS 109's students said they felt unsafe at the school, although all the teachers reported feeling safe.

The tragedy occured just two days after Chancellor Dennis Walcottjoined City Council Speaker Christine Quinn in askingschools to step up antii-bullying efforts before the end of the school year.

Walcott mentioned the latest anti-bullying initiative at a Town Hall meeting in Bedford Stuyvesant on Monday night, telling parents that bullying was still "very prevalent" in city schools. Just two days later, according to the Daily News, he was comforting the family of Gabrielle Molina, a student at IS 109 Jean Nuzzi Middle School, who was found dead that afternoon.

"Any child that takes his life or her life is something that deeply concerns me and hurts me as a parent and not just as a chancellor,” Walcott told the Daily News on Thursday. "Bullying is something that I feel very strongly about. We are always looking at new ways to work on the issue."

Earlier this week, Walcott's letter to principals asked them to "incorporate anti-bullying lessons into end-of-year assemblies, programs, and curricula." He suggested they host school assemblies, classroom or advisory lessons, reading circles, peer-led workshops or activities with outside organizations, and pointed to a website with resources for teachers.

In recent years, the DOE has launched a campaign against bullying, for example making it easier for victims of bullying to transfer to a different high school, and adding a Chancellor's Regulation, outlining procedures for students to report incidents of bullying at school. Each school is expected to have a counselor available for students and to hold a Respect for All week to promote student understanding of other cultures and a respect for diversity. Last year the teachers union established an anti-bullying hotline number -- 212-709-3222 --  and even held an anti-bullying fair in March.

Yet, none of the actions prevented a troubled middle school student from taking her own life, or addressed an apparent disconnect between students' and teachers' perceptions of bullying and safety at the school.

Walcott will be visiting IS 109 on Friday and grief counselors will be available for staff and students. Perhaps, in the aftermath, teachers and students can work together to develop or adopt anti-bullying measures that might help prevent similar tragedies.