green trees beside body of water under blue sky and white clouds during daytime

On 22 July 2011, a mass shooting took place at the AUF's summer youth camp, where 650 young people were staying. Anders Behring Breivik arrived alone on Utøya dressed as a police officer and told those on the island that he was there for security reasons following the explosions in Oslo which took place a few hours before. He then began shooting at individuals, continuing until the police arrived one hour after the first alarm call. The suspect immediately surrendered.[6] Combined, the attacks in Oslo and Utøya left 77 dead, with 69 killed on the island, 33 of whom were under the age of 18.