“4:30 P.M., TUESDAY, AUGUST 14, 1945.” So began associate editor Anne Stern’s article in the August 17 California Daily Bruin, noting the exact time when UCLA’s air-raid siren sounded the “all-clear” signal, indicating the end of World War II.

“Late campus habituees [sic] came pouring out of the library, labs, late classes,” Stern wrote. Celebrations erupted across campus, almost four years after the United States had declared war on Japan following its attack on Pearl Harbor.

When the U.S. entered World War II in December 1941, so did UCLA. Many male students — and some female — left to serve in the military, to be eventually replaced by new “students”: defense industry workers and others eager to improve their skills or gain new ones in UCLA’s Engineering, Science and Management War Training program. Bruins still in school sold war bonds, planted victory gardens and organized blood drives. For them, men in military uniforms were a familiar sight, training around campus, chowing down in “Kerckhoff Mess” and bunking in converted fraternity houses.

While the campus was on high alert — with enough food for 50,000 people reportedly stashed under the Arroyo Bridge, in case of attack — the university’s most clandestine wartime activity took place in downtown Los Angeles, in the UCLA Extension building. Codenamed Project 36, the top-secret operation involved UCLA in the development of the first atomic bomb. While scientists toiled in a laboratory in Los Alamos, N.M., under a government contract with the University of California, UCLA’s task was to purchase and deliver the equipment and materials necessary for the success of the Manhattan Project — from rats to 10-ton trucks to meteorological balloons. Suppliers often questioned the university’s unusual orders, and UCLA purchasing agents took items such as typewriters and microscopes from campus labs, unaware of how their acquisitions would be used.

Faculty members also assisted in the war effort. Some supervised training programs for the military personnel on campus; others took extended leaves to work for the government, research laboratories or the armed forces. A key contributor to the U.S. defense effort was Physics Professor Vern O. Knudsen, an expert in acoustics. At the U.S. Navy Radio and Sound Laboratory in San Diego, he conducted classified research on underwater sound, which led to the development of an acoustic torpedo that could track the sound of submarine propellers — a major breakthrough in the war against German U-boats.

By the war’s end, several thousand UCLA students and alumni had served on the front lines. Among them was Hitoshi “Moe” Yonemura, a popular yell leader and student body officer, who, like others of Japanese descent, was sent to an internment camp in 1942. Eventually, he transferred to the U.S. Army’s Japanese-American 442nd Regimental Combat Team and was killed in Italy in April 1945.

Thanks to the wartime contributions of UCLA students, faculty and staff — and others like them — Anne Stern and other Bruins finally had reason to celebrate on that August day 70 years ago.