05/01/2012 at 02:00 PM EDT
Norwegian swimmer Alexander Dale Oen, considered to be one of his country's biggest medal hopefuls at this summer's London Olympics
, died suddenly from cardiac arrest at a pre-Olympic
training camp, the AP reports. He was 26.
Dale Oen was found on his bathroom floor in Flagstaff, Ariz., late Monday after going through a light training session and playing some golf. He was pronounced dead shortly after at Flagstaff Medical Center, according to the AP.
Teammates grew concerned when Dale Oen didn't respond to their knocks on his bathroom door after they said he spent an unusually long time in the shower.
According to a statement by the Norwegian swimming federation, they found him "laying partly on the floor, partly on the edge of his bathtub." A team doctor began performing CPR immediately until an ambulance came.
"We're all in shock," Norwegian swimming coach Petter Loevberg said in a statement. "This is an out-of-the-body experience for the whole team over here. Our thoughts primarily go to his family who have lost Alexander way too early."
A hospital spokesperson also confirmed his death.
Dale Oen won an 100-meter breaststroke at 2011's World Championships in Shanghai. His victory came three days after a massacre which killed 77 people, including children from a summer camp in his native Norway.
He dedicated that win to victims of the shooting spree, saying at the time, "We need to stay united. Everyone back home now is of course paralyzed with what happened, but it was important for me to symbolize that even though I'm here in China, I'm able to feel the same emotions."
News of Dale Oen's sudden death was major news on Tuesday in Norway, and the country's prime minister, Jens Stoltenberg, Tweeted his condolences
, writing, "Alexander Dale Oen was a great sportsman for a small country. My thoughts go to his family and friends."