Because of the rumors that a Japanese aircraft carrier was cruising off the coast of the San Francisco Bay Area, 500 United States Army troops moved into Walt Disney Studios lot to defend the Hollywood facility, and contributing to the paranoia was the fact that many American merchant ships were attacked by Japanese submarines in waters off the West Coast.
The attack on Pearl Harbor by Imperial Japan on December 7, 1941 brought America into World War II. 500 United States Army soldiers of the 121st Anti-Aircraft Artillery (AAA) Gun Battalion occupied Walt Disney Studios the day after the attack for eight months in the period of the West Coast invasion scare, earning Disney as the only Hollywood studio to come under military occupation in history. 
