Flags flew at half-staff as people lay flowers and children blew soap bubbles outside the cathedral in Norway's capital Sunday to pay tribute to the 77 people killed in last month's bombing and shooting massacre by a right-wing extremist. A memorial service later in the day will mark the end of a month of mourning in the Scandinavian country that was shocked by the attacks in what is a prosperous and generally tolerant and tranquil society. The memorial at the Spektrum Arena in central Oslo, which also hosts the Nobel Peace Prize Concert, will be broadcast live on national television and will be attended by the families of victims and survivors of the July 22 car bombing and shooting spree. Norway's King Harald and Prime Minister Jens Stoltenberg will address the ceremony, to be attended by government members, lawmakers and leading politicians and royals from neighboring countries.