From an 11-year-old watching the towers fall on a classroom TV to a doctor treating victims in a conference room, NBC News readers share their searing memories from Sept. 11, 2001.

In Alabama, Sept. 11 fits into “military involvement in international conflicts since 1980," while Texas teaches an example of “radical Islamic terrorism."

After 25 years, 100 million Americans have no memory of the day that changed everything. In an age of social media, disinformation and mistrust, that can be dangerous.

Grieving a day—and dad—I don’t remember.

From Gen Z to the Silent Generation, Americans told USA TODAY about their memory of 9/11.