NO WAY would I allow a kid of mine to study Islam in school. I'd be the one to teach my kid about Islam. And 9-11 would be where I would start.
We should teach our children about Islam. But, don't start with 9-11. Start with Mohammad. There is plenty to learn that creates a perfect contrast to Jesus Christ. You could start with how Mohammad, while fasting, had delusional visions in a cave which he thought was the word of God. Then you can teach the orginal acts of terror under Islam as the Mohammedans attacked merchant caravans traveling from Syria to Mecca. This started the first of three Meccan wars, after each, Mohammad eliminated a tribe of Jews living in Medina. Then of course there is the spread of Islam - by the sword. When the children are a little older, they can also learn how Mohammad was a pedophile. For greatest impact, the lessons should include modern day practices of Islam in Saudi Arabia, Iran and around the world.