Nagasaki (nägˌäsäˈkē) [key], city (1990 pop. 444,599), capital of Nagasaki prefecture, W Kyushu, Japan, on Nagasaki Bay. It is one of Japan's leading ports. Shipbuilding is the chief industry; steelworks, collieries, fisheries, and electrical machinery plants are also important. Nagasaki's port, the first to receive Western trade, was known to Portuguese and Spanish traders before it was opened to the Dutch in 1567. After the Portuguese and Spanish merchants were forced to leave Japan in 1637, the Dutch traders were restricted (1641–1858) to De-shima, an island in the harbor. Nagasaki was gradually reopened to general foreign trade during the 1850s. Long a center of Christianity, the city had until 1945 Japan's largest Roman Catholic cathedral. During World War II, on Aug. 9, 1945, Nagasaki became the target of the second atomic bomb ever detonated on a populated area; about 75,000 people were killed or wounded, and more than one third of the city was devastated. Among Nagasaki's landmarks is Glover Mansion, scene of Puccini's opera Madama Butterfly. Nagasaki prefecture (1990 pop. 1,563,015), 1,574 sq mi (4,077 sq km), is mainly agricultural. Raw-silk production is widespread, and coal is mined near Sasebo. Important cities are Nagasaki, Hirado, known for its fine porcelain ware, and Sasebo, the site of a large naval base. The prefecture includes the island of Goto-retto.