At work when it happened, after first plane went into tower (heard it on the radio), everyone rushed into the rest room to see it on the news, was like watching a hollywood film, so hard to believe it was all happening live on TV.
Then later that day, the base was all recalled for the possible arrival of civilian jets landing on our base, still dunno why to be honest, but didn't happen anyways. Then obviously base was on high alert for a while after 9/11.