Four teens were arrested Friday on suspicion of vandalism at a cave in Okinawa Prefecture where civilians were forced to commit mass suicide in the closing days of World War II, police said.The boys aged 16 to 19 have admitted to destroying with sticks two signboards and origami paper cranes left by visitors to the Chibichirigama cave in the village of Yomitan last Sunday, saying they went to "a haunted spot" on a motorbike to "test their courage," according to investigators.During the Battle of Okinawa, which started on April 1, 1945 with the landing of U.S. forces on the southern Japanese…READ FULL ARTICLE