On 9 February 2001, about nine nautical miles south of Oahu, Hawaii, in the Pacific Ocean, the United States Navy (USN) Los Angeles-class submarine USS Greeneville (SSN-772) collided with the Japanese fishery high-school training ship Ehime Maru (えひめ丸) from Ehime Prefecture. In a demonstration for some VIP civilian visitors, Greeneville performed an emergency ballast blow surfacing maneuver. As the submarine shot to the surface, she struck Ehime Maru. Within ten minutes of the collision, Ehime Maru sank. Nine of the thirty-five people aboard were killed: four high school students, two teachers, and three crew members.