We’ve made a list of books for kids who may have questions about the terrorist attacks of 20 years ago. Find the list here.
And, librarians and archivists at the Internet Archive made a conscious effort right after the attacks to preserve the television news reports from September 11, 2001 and the days that followed. These may not have been preserved otherwise. They are available in a curated presentation online at https://archive.org/details/911.