You can visit the 9/11 Memorial Preview Site to learn about the plans and progress for the memorial and museum being built at the World Trade Center site.
I have been here several times and no matter what, it is still a sad place to visit. It just looks like a construction area. They have boards up all around with the names of all of the victims in the 911. It is very touching just to go and see everything yourself. I do recommend that anybody who can see this, go see it.
When you are in this part of town you will want to stop and see the Memorial for the victims of 9/11. It is very moving. I also liked the things I could buy for friends back home here knowing proceeds were going to the Memorial. They had an interesting selection of children's books as well as other great memorial items. The huge bargain store Century 21 and St Peters Catholic Church are close by.
We hadn't been to New York City since before 9/11, so this trip we made it a point to visit the WTC site and the 9/11 Memorial Preview Site museum. Our children were born in a post-9/11 world, but at various times we had attempted to describe to them what had occurred on September 11, 2001. We had a group of young kids with us, those on the younger side (under 5) didn't seem to grasp the gravity of what had happened. The older kids who were 7 years old, did grasp it. We fielded a lot of questions from the older ones and definitely helped them to process through the sadness of it all (a word that was used by their own mouths to describe how they felt). The 9/11 Memorial Preview Site museum is a much needed place which helps one to learn and process. The images and videos are well done and convey the enormity of the senseless loss of life. I found myself tearing up. Be sure to use your judgement and make sure you describe what is happening to your little ones if they are of appropriate age. I give it four stars. It's not a family "friendly" activity per say, but it is certainly an educational one.