Many of us can remember the moment when the Twin Towers came down on September 11, 2001. This tribute, 15 years later, is to remember the day and honor its victims, and help those who may not understand or fully remember the significant events and responses to the worst attack on American soil since Pearl Harbor.

(A word of caution: the details of that day can be disturbing as anyone who lived through the day or witnessed its events already knows. We tried to prepare an account suitable for families.)