I have searched for something during the time periods that you requested that might compare to 9/11. I found very little during those years that might compare to the scale of events that occurred on 9/11/2001. I have offered a few bits of information that might be helpful to you. The most popular comparison between 9/11 is to Japan's attack on Pearl Harbor in 1941. "... five of eight battleships at Pearl Harbor were sunk or sinking, with the rest damaged. Several other ships and most Hawaii-based combat planes were also knocked out and over 2400 Americans were dead." (http://www.history.navy.mil/photos/events/wwii-pac/pearlhbr/pearlhbr.htm)
1941 Dec. 7, Japan bombed Pearl Harbor.
1963 Nov 9, Twin disasters struck Japan as some 450 miners were killed in a coal-dust explosion, and 160 people died in a train crash.
1966 Mar 4, Canadian Pacific airliner exploded on landing in Tokyo and 64 died.
1966 Mar 5, 75 MPH air currents caused a BOAC 707 to crash into Mount Fuji and 124 died. (http://timelines.ws/countries/JAPAN_1941.HTML)
The Battle of Britain 10 July to 31 October 1940. 544 lost their lives during the period of the Battle. A further 791 were killed in action or died in the course of their duties before the wars end. (http://www.raf.mod.uk/Bob1940/roll.html)