A deep-sea expedition has captured video of three Second World War shipwrecks dating to the Battle of Midway in June 1942. The aircraft carrier USS Yorktown, built for the <a href="https://www.thenationalnews.com/world/us-news/" target="_blank">US</a> Navy in the 1930s, was discovered by the Ocean Exploration Trust team during a search of one of the largest protected areas in the US. During the 27-day expedition to Hawaii's Papahanaumokuakea Marine National Monument in September, the crew also filmed wreckage of the Imperial Japanese Navy's Akagi and Kaga, carriers that sent planes to attack Pearl Harbour in December 1941. The IJN Kaga was found 5.4km below the surface of the Pacific. It was struck by bombs during the battle in 1942, before it was engulfed in flames. To prevent its capture, a Japanese ship caused the Kaga to sink. "Each dive on Battle of Midway cultural heritage sites was launched and closed with protocol ceremonies to honour this place and all who lost their lives in ways that reflected their significance to Kanaka ʻOiwi [Native Hawaiian], Japanese and US military families and communities," the trust said. The region is a Unesco World Heritage Site and the US's largest marine protected area at 1.5 million square kilometres. Large parts are still unexplored.