Following the Japanese attack on Pearl Harbor on Dec. 7, 1941, the United States military increased defense preparations at all West Coast cities and ports. Los Angeles, with its major industry and aircraft manufacturing plants, was especially important to protect.
Los Angeles Times photographer Paul Calvert and writer John Cornell documented the U.S. Army fortifications and training around Southern California. Working with military censors, they were able to gain access to various Army units, but with major restrictions. The actual units and locations of bases could not be revealed.
U.S. Army anti-aircraft gun live fire exercise at undisclosed California beach location.
(via Southern California defenses. Visual Storytelling from the Los Angeles Times)