Last spring, Tom Buxton was horrified when a sixth-grade student told him she thought 9/11 was an accident.
"An accident. That was it," recalled Buxton, a New York City English teacher in Brooklyn.
The student's inaccurate statement prompted him to devote an entire year of his English class to teaching students about 9/11.
Along with the 9/11 Museum, the city Department of Education created a curriculum for teachers to teach 9/11, which can be used in K-12 social studies, history or English classes. But Buxton felt the pre-planned curriculum lacked a human element. He invited guest lecturers, like a man who lost a relative in the towers and a person who carried another in a wheelchair down 62 floors to speak to his seventh-grade class.
"For two hours, you didn't hear a chair move," he said.
Closer to home in Philadelphia, on the anniversary of the 9/11 terrorist attacks, many students will not only be learning about the tragic events of that day, but how they can make their communities a safer place to live.
In the School District of Philadelphia, teachers are encouraged to use the day to launch community service projects, an idea that came from President Obama's message of volunteerism.
"What we want people to understand is we always need to remember to give to other no matter how difficult the hardship seems to be," said Donna Runner, the district's assistant superintendent for curriculum and instruction.
In the lower grades, students often discuss heroes from 9/11 and how to live together peacefully. In the higher grades, students discuss the events and how they have affected domestic and international policy, Runner said.
Students at Mariana Bracetti Academy Charter School in Kensington will get to a visit from a first-responder from 9/11. Chris Suprun, a veteran paramedic, will talk about being prepared in life and in an emergency.
Advice on how to talk to kids about 9/11
Dr. Mary Pulido, director of the New York Society for the Prevention of Cruelty to Children, said disaster should be approached delicately with children.
"The little ones, kindergarteners down, they shouldn't even know what 9/11 is at this point," she said. "Eleven or 12-year-olds, they were born or one or two years, so I doubt they'll have vivid memories of it at that age."
These children may come home from school today wondering about Sept. 11, or perhaps have a friend with a personal connection.
"Let them bring it up," she advises. Say something like, "Why do you think we're remembering the anniversary?" or "What did you hear in school about Sept. 11?"