The photo above ran in the Los Angeles Times on Feb. 26, 1942 

Just months after the U.S. entered World War II, mounting fears of an invasion from Japan put U.S. coastal defenses on standby. And in the early morning hours of February 25th, 1942 they went into action when an unknown object was detected as it made its way inland towards Los Angeles from the Pacific Ocean. Air raid sirens sounded, a total blackout was ordered for the city and surrounding areas, radio stations were ordered off the air and massive searchlights began scanning the sky for the unknown intruder. Then, just after 3am, the night erupted with the continuous sound of anti-aircraft guns firing on an unknown object. Despite the constant barrage, the mystery craft was unfazed by the attack and made its way slowly southward down the coast. At one point the firing ceased when the object was no longer seen, but began again when it made its way back inland for a second time. After more than 1,400 direct rounds were fired in an attempt to knock down the intruder, it was reported to have headed back out towards the Pacific Ocean until it could no longer be seen.

Witness accounts have added another layer of mystery to the event. Some claiming U.S. planes were in pursuit of the object, another mentions a downed ‘plane’ that was quickly cordoned off by local authorities, while some describe the object itself in great detail as they watched it fly overhead, and another tells of a secret Naval mission launched off the coast to retrieve the potentially downed craft from deep in the ocean.