The Battle of Los Angeles, also known as The Great Los Angeles Air Raid, is the name given by contemporary sources to the rumored enemy attack and subsequent anti-aircraft artillery barrage which took place from late February 24 to early February 25, 1942 over Los Angeles, CA. The incident occurred less than three months after America's entry into World War II as a result of the Japanese Imperial Navy's attack on Pearl Harbor. Air raid sirens were sounded throughout Los Angeles County on the night of 24–25 February 1942. A total blackout was ordered and thousands of air raid wardens were summoned to their positions. At 3:16 a.m. the 37th Coast Artillery Brigade began firing 12.8-pound anti-aircraft shells into the air at reported aircraft; over 1,400 shells would eventually be fired. Pilots of the 4th Interceptor Command were alerted but their aircraft remained grounded. The artillery fire continued sporadically until 4:14 a.m. The "all clear" was sounded and the blackout order lifted at 7:21 a.m. In addition to several buildings damaged by friendly fire, three civilians were killed by the anti-aircraft fire, and another three died of heart attacks attributed to the stress of the hour-long bombardment. The incident was front-page news along the U.S. Pacific coast, and earned some mass media coverage throughout the nation. Initially, the target of the aerial barrage was thought to be an attacking force from Japan, but speaking at a press conference shortly afterward Secretary of the Navy, Frank Knox called the incident a "false alarm." Newspapers of the time published a number of sensational reports and speculations of a cover-up. A small number of modern-day UFOlologists have suggested the targets were extraterrestrial spacecraft. When documenting the incident in 1983, the U.S. Office of Air Force History attributed the event to a case of "war nerves" likely triggered by a lost weather balloon and exacerbated by stray flares and shell bursts from adjoining batteries. for more on this go here.