After the war ended in 1945, the Japanese government declared that they had flown no airplanes over Los Angeles during the war.[13] In 1983, the U.S. Office of Air Force History concluded that an analysis of the evidence points to meteorological balloons as the cause of the initial alarm:[12]
During the course of a fireside report to the nation delivered by President Roosevelt on 23 February 1942, a Japanese submarine rose out of the sea off Ellwood, a hamlet on the California coast north of Santa Barbara, and pumped thirteen shells into tidewater refinery installations. The shots seemed designed to punctuate the President's statement that "the broad oceans which have been heralded in the past as our protection from attack have become endless battlefields on which we are constantly being challenged by our enemies." Yet the attack which was supposed to carry the enemy's defiance, and which did succeed in stealing headlines from the President's address, was a feeble gesture rather than a damaging blow. The raider surfaced at 1905 (Pacific time), just five minutes after the President started his speech. For about twenty minutes the submarine kept a position 2,500 yards offshore to deliver the shots from its 5½-inch guns. The shells did minor damage to piers and oil wells, but missed the gasoline plant, which appears to have been the aiming point; the military effects of the raid were therefore nil. The first news of the attack led to the dispatch of pursuit planes to the area, and subsequently three bombers joined the attempt to destroy the raider, but without success. The reluctance of AAF commanders to assign larger forces to the task resulted from their belief that such a raid as this would be employed by the enemy to divert attention from a major air task force which would hurl its planes against a really significant target. Loyal Japanese-Americans who had predicted that a demonstration would be made in connection with the President's speech also prophesied that Los Angeles would be attacked the next night. The Army, too, was convinced that some new action impended, and took all possible precautions. Newspapers were permitted to announce that a strict state of readiness against renewed attacks had been imposed, and there followed the confused action known as "The Battle of Los Angeles".
During the night of 24/25 February 1942, unidentified objects caused a succession of alerts in southern California. On the 24th, a warning issued by naval intelligence indicated that an attack could be expected within the next ten hours. That evening many flares and blinking lights were reported from the vicinity of defense plants. An alert called at 1918 [7:18 pm, Pacific time] was lifted at 2223, and the tension temporarily relaxed. But early in the morning of the 25th renewed activity began. Radars picked up an unidentified target 120 miles west of Los Angeles. Antiaircraft batteries were alerted at 0215 and were put on Green Alert—ready to fire—a few minutes later. The AAF kept its pursuit planes on the ground, preferring to await indications of the scale and direction of any attack before committing its limited fighter force. Radars tracked the approaching target to within a few miles of the coast, and at 0221 the regional controller ordered a blackout. Thereafter the information center was flooded with reports of "enemy planes, " even though the mysterious object tracked in from sea seems to have vanished. At 0243, planes were reported near Long Beach, and a few minutes later a coast artillery colonel spotted "about 25 planes at 12,000 feet" over Los Angeles. At 0306 a balloon carrying a red flare was seen over Santa Monica and four batteries of anti-aircraft artillery opened fire, whereupon "the air over Los Angeles erupted like a volcano." From this point on reports were hopelessly at variance.
Probably much of the confusion came from the fact that anti-aircraft shell bursts, caught by the searchlights, were themselves mistaken for enemy planes. In any case, the next three hours produced some of the most imaginative reporting of the war: "swarms" of planes (or, sometimes, balloons) of all possible sizes, numbering from one to several hundred, traveling at altitudes which ranged from a few thousand feet to more than 20,000 and flying at speeds which were said to have varied from "very slow" to over 200 miles per hour, were observed to parade across the skies. These mysterious forces dropped no bombs and, despite the fact that 1,440 rounds of anti-aircraft ammunition were directed against them, suffered no losses. There were reports, to be sure, that four enemy planes had been shot down, and one was supposed to have landed in flames at a Hollywood intersection. Residents in a forty-mile arc along the coast watched from hills or rooftops as the play of guns and searchlights provided the first real drama of the war for citizens of the mainland. The dawn, which ended the shooting and the fantasy, also proved that the only damage which resulted to the city was such as had been caused by the excitement (there was at least one death from heart failure), by traffic accidents in the blacked-out streets, or by shell fragments from the artillery barrage.
Attempts to arrive at an explanation of the incident quickly became as involved and mysterious as the "battle" itself. The Navy immediately insisted that there was no evidence of the presence of enemy planes, and [Secretary of the Navy], Frank Knox announced at a press conference on 25 February that the raid was just a false alarm. At the same conference he admitted that attacks were always possible and indicated that vital industries located along the coast ought to be moved inland. The Army had a hard time making up its mind on the cause of the alert. A report to Washington, made by the Western Defense Command shortly after the raid had ended, indicated that the credibility of reports of an attack had begun to be shaken before the blackout was lifted. This message predicted that developments would prove "that most previous reports had been greatly exaggerated." The Fourth Air Force had indicated its belief that there were no planes over Los Angeles. But the Army did not publish these initial conclusions. Instead, it waited a day, until after a thorough examination of witnesses had been finished. On the basis of these hearings, local commanders altered their verdict and indicated a belief that from one to five unidentified airplanes had been over Los Angeles. Secretary Stimson announced this conclusion as the War Department version of the incident, and he advanced two theories to account for the mysterious craft: either they were commercial planes operated by an enemy from secret fields in California or Mexico, or they were light planes launched from Japanese submarines. In either case, the enemy's purpose must have been to locate anti-aircraft defenses in the area or to deliver a blow at civilian morale.
The divergence of views between the War and Navy departments, and the unsatisfying conjectures advanced by the Army to explain the affair, touched off a vigorous public discussion. The Los Angeles Times, in a first-page editorial on 26 February, announced that "the considerable public excitement and confusion" caused by the alert, as well as its "spectacular official accompaniments", demanded a careful explanation. Fears were expressed lest a few phony raids undermine the confidence of civilian volunteers in the aircraft warning service. In the United States Congress, Representative Leland Ford wanted to know whether the incident was "a practice raid, or a raid to throw a scare into 2,000,000 people, or a mistaken identity raid, or a raid to take away Southern California's war industries." Wendell Willkie, speaking in Los Angeles on 26 February, assured Californians on the basis of his experiences in England that when a real air raid began "you won't have to argue about it—you'll just know." He conceded that military authorities had been correct in calling a precautionary alert but deplored the lack of agreement between the Army and Navy. A strong editorial in the Washington Post on 27 February called the handling of the Los Angeles episode a "recipe for jitters", and censured the military authorities for what it called "stubborn silence" in the face of widespread uncertainty. The editorial suggested that the Army's theory that commercial planes might have caused the alert "explains everything except where the planes came from, whither they were going, and why no American planes were sent in pursuit of them." The New York Times on 28 February expressed a belief that the more the incident was studied, the more incredible it became: "If the batteries were firing on nothing at all, as Secretary Knox implies, it is a sign of expensive incompetence and jitters. If the batteries were firing on real planes, some of them as low as 9,000 feet, as Secretary Stimson declares, why were they completely ineffective? Why did no American planes go up to engage them, or even to identify them? ... What would have happened if this had been a real air raid?" These questions were appropriate, but for the War Department to have answered them in full frankness would have involved an even more complete revelation of the weakness of American air defenses.
At the end of the war, the Japanese stated that they did not send planes over the area at the time of this alert, although submarine-launched aircraft were subsequently used over Oregon. A careful study of the evidence suggests that meteorological balloons—known to have been released over Los Angeles—may well have caused the initial alarm. This theory is supported by the fact that anti-aircraft artillery units were officially criticized for having wasted ammunition on targets which moved too slowly to have been airplanes. After the firing started, careful observation was difficult because of drifting smoke from shell bursts. The acting commander of the anti-aircraft artillery brigade in the area testified that he had first been convinced that he had seen fifteen planes in the air, but had quickly decided that he was seeing smoke. Competent correspondents like Ernie Pyle and Bill Henry witnessed the shooting and wrote that they were never able to make out an airplane. It is hard to see, in any event, what enemy purpose would have been served by an attack in which no bombs were dropped, unless perhaps, as Mr. Stimson suggested, the purpose had been reconnaissance.
According to historian Roger Lotchin, "the incident became derisively termed 'The Battle of Los Angeles' or 'The Great Los Angeles Air Raid' and is often cited as an example of the buffoonery that suffused the war effort in the state".[5]
