Any life lost is a saddened time, and since I used to swim year round, and I don't have to know AD Oen personally but in the world of swimming it's a close knit family no matter throughout the world where swimmers all live. My heartfelt condolences are sent out to his family, as well as his swimming family. If he had any pets, to them too for they miss their best friend.
I'm in the US, but I hope the Norwegian Olympic Team thinks up an idea in honor of their team mate with something to wear maybe on their Olympic attire entering the stadium. Just a thought.
Good luck in London to all Worldwide Competitors for I'm excited for each and every one of you who make it.