Port Arthur 20th Anniversary Commemoration Service

PORT ARTHUR, AUSTRALIA - APRIL 28: A yellow rose is seen in what once was the Broad Arrow Cafe during the 20th anniversary commemoration service of the Port Arthur massacre on April 28, 2016 in Port Arthur, Australia. The historic town became infamous on April 28, 1996 when Martin Bryant began shooting indiscriminately with a high-powered rifle on people visiting the site. 35 people were killed and a further 23 were injured in what remains the world's worst massacre by a lone gunman. The tragedy transformed gun legislation in Australia, with then Prime Minister John Howard introducing the National Firearms Agreement, banning all semi-automatic rifles and all semi-automatic and pump-action shotguns and introducing stricter licensing and ownership controls. (Photo by Robert Cianflone/Getty Images)