A live-fire exercise sank the former Navy ship Niagara Falls southwest of Kauai on Saturday, the Navy said.
The exercise was part of the Rim of the Pacific (RIMPAC) 2012 naval exercises.
“These exercises provide important opportunities for realistic at-sea training with live ordnance, conditions that cannot be duplicated otherwise,” Vice Adm. Gerald Beaman, 3rd Fleet commander, said in a statement Sunday.
The ship went down in waters 15,480 feet deep, 63 miles southwest of Kauai about 11:31 a.m. Saturday, the Navy said.
The Navy says a sinking exercise or SINKEX gives crews the opportunity to gain proficiency in tactics, targeting and live firing against surface targets, which enhances combat readiness of deployable units.
The former USS Niagara Falls was a Mars-class combat stores ship commissioned in April 1967, decommissioned and transferred to Military Sealift Command in September 1994 and deactivated in September 2008.
Twenty-two nations, more than 40 ships and submarines, more than 200 aircraft and 25,000 personnel are participating in RIMPAC exercise through Aug. 3 in and around the Hawaiian Islands.