Two years ago, 600 teenagers gathered for a summer camp on the tiny Norwegian island of Utøya.
An annual event organised by the country’s largest political youth organisation, the camp was a perfect opportunity to combine their passion for politics with traditional activities like bonfires, swimming, volleyball and meeting like minds.
These kids should have looked back on their time on Utøya with a smile. Instead their lives, and those of their families, were forever changed by the actions of a lone gunman.
Around 3:30pm on July 22, 2011, eight people were killed and dozens injured when a homemade car bomb detonated at the executive government building in central Oslo.
That same afternoon, 33-year-old Anders Behring Breivik made his way to Utøya where, dressed as a policeman and armed with an automatic rifle and handgun, he opened fire, killing 69 people and injuring over 100 more.
It was the worst peacetime atrocity in Norway's history, and the small nation was overwhelmed with grief in the wake of the tragedy. A survey conducted afterwards estimated that one in four Norwegians knew somebody directly affected by the massacre.
One of the survivors, Emma Martinovic, 18, gave a chilling account of the events of July 22 in a blog post:
I saw a body face down in the water. I waded out, all the while looking skywards and praying. I dragged the boy's body back to land and when I pulled back his jacket hood I saw it was a friend of mine, and I saw the wound to his head. There was no time to react.
I saw one of my friends about to leap into the water, but in a second he was shot. Even at a distance I could see and hear the two shots, straight to the head. I saw his head explode, I saw how he was split apart. Panic spread like wildfire among those on land. I wanted to be among them, urging them to get away, by land or water. I even yelled: "Swim or run!", but nothing helped, there was so much other noise – both the helicopter above us and the bastard's rifle.
Suddenly someone behind me shouts. "Emma, I can't go on."
It was one of my girlfriends. I gritted my teeth and swam back to her, then told her to keep the rhythm: Breathe for you and breathe for me. We'll soon be safe and warm, you'll see.
Suddenly she said: "Emma, you're bleeding", and when I looked down at my left arm, there was blood pouring from it. I tried to shut it out, focus on swimming, but I knew full well why my left arm was aching so much, but I didn't want to stop. Behind us we could still hear shooting, the screams, the laughter of the bastard as he shot, and his shout to us: "You won't get away!"
Now, two years after the shooting, a series of moving portraits titled "One Day in History" depict the profound emotional and physical injuries sustained by survivors.
Andrea Gjestvang was working as a photo editor in Oslo when Breivik's car bomb exploded. After sprinting home to retrieve her equipment, she began photographing the carnage of the attack.
In an email to Slate's David Rosenberg, Gjestvang explains that taking photos helped her process the unthinkable horror taking place before her eyes.