 It also had a copper mine that contained 1/10 of all of Japan's copper.Following an air raid on June 10 by the USAAF, which missed the Hitachi factories and burned down much of the civilian residential districts, the city was subjected to shore bombardment on July 19 by the battleships , , and .However, the bombardment was very inaccurate, and although civilian casualties were very high, the Hitachi factories were again largely left intact.