File photos of the 'Bloody Sunday' protest on 30 January 1972, of the funeral of the victims, and of a protest that took place a month later in Londonderry. The Northern Irish city of Londonderry commemorates one of the darkest days in modern UK history on Sunday when, 50 years ago, British troops opened fire without provocation on civil rights protesters. The anniversary of "Bloody Sunday" comes with Northern Ireland's fragile peace destabilised by Brexit, and with families of the victims despondent over whether the soldiers involved will ever face trial. FILE PHOTOS