I was in school...a Catholic school...when in the afternoon the principal came on the PA system and announced that something terrible had happened but she didn't give any details. The announcement was about 20 seconds long.
After the announcement some of us were afraid that the Russians were gonna attack. So any time we heard a plane fly overhead we were afraid it would drop a bomb on us.
I was too young when JFK happened, but I always imagined that 9/11 was as close as to experiencing the feelings of that day.