In August 1944, they were discovered and deported to Nazi concentration camps. They were long thought to have been betrayed, although there are indications that their discovery may have been accidental, that the police raid had actually targeted "ration fraud". Of the eight people, only Otto Frank survived the war. Anne was 15 years old when she died in Bergen-Belsen. The exact date of her death is unknown, and has long been believed to be in late February or early March, a few weeks before the prisoners were liberated by British troops on 15 April 1945.