For young children in school, 9-11 is a history lesson that teachers say isn't an easy task to teach.
10-year-old Blake Donaldson is a 5th grader who says "the twin towers got destroyed... and the Pentagon got destroyed too."
In Pat Dunckel's 5th grade class, students have a hard time believing something like this would happen.
"They go to the airports, they know about all the airport security. They don't even understand how these terrorists got on the airplane," said Dunckel. "They also don't understand the idea of why someone would want to do this."
"(Reporter) How does it make you feel? (Blake) Really sad. (Reporter) How come? (Blake) Because a lot of people died."
"Mrs. Hewitt said that the people in the twin towers, they were calling their loved ones and stuff and the people in the towers were basically saying goodbye," said 8th grader Michael Folley.
Kim Hewitt is Michael's teacher and says she is surprised many students hadn't seen the video of the attack.
"About 85 percent, 90 percent of these kids, today was the first time they had seen that footage," said Hewitt.
"Unfortunately, I think they see a lot of that violence in video games and in TV and the video I show, shows the towers falling, shows the fires, we don't get into the real graphic parts of it," said Dunckel. "I want them to accept people that are different and to be able to respect their differences and use words instead of violence to try to convince them maybe of a different viewpoint," said Dunckel.