The Battle of Los Angeles

On February 24, 1942, less than three months after the Japanese bombed Pearl Harbor, military radar picks up what appears to be enemy aircraft over Los Angeles. Air raid sirens send citizens scrambling, as troops fire more than 1400 rounds of anti-aircraft artillery at the illusive targets. When the smoke clears, the incident is veiled in secrecy and lies. What exactly triggered the so-called Battle of Los Angeles?