Powerful video shows the moment an avalanche hit a base camp on Mount Everest.

The avalanche was triggered by a massive, 7.8-magnitude earthquake in Nepal. More than 3,700 have been killed in the earthquake, and the death toll could rise.

Three Americans were among those killed in the avalanche. The victims were Tom Taplin, a documentary filmmaker who was making a movie about the base camp, Marisa Eve Girawong, a doctor working with a climbing group, and Google executive Dan Fredinburg, who was climbing Everest to map it for a new Google feature.

Fredinburg dated “One Tree Hill” star Sophia Bush in 2013 and 2014. She posted a touching tribute to her ex-boyfriend on Instagram, calling him one-of-a-kind, fearless and funny.

"He was one of my favorite human beings on Earth. He was one of the great loves of my life. He was one of my truest friends. He was an incredible brother, a brilliant engineer, and a damn good man," she wrote.

 

There are no adequate words. Today I find myself attempting to pick up the pieces of my heart that have broken into such tiny shards, I'll likely never find them all. Today I, and so many of my loved ones, lost an incredible friend. Dan Fredinburg was one-of-a-kind. Fearless. Funny. A dancing robot who liked to ride dinosaurs and chase the sun and envision a better future for the world. His brain knew how to build it. His heart was constantly evolving to push himself to make it so. He was one of my favorite human beings on Earth. He was one of the great loves of my life. He was one of my truest friends. He was an incredible brother, a brilliant engineer, and a damn good man. I'm devastated and simultaneously so deeply grateful to have known and loved him, and to have counted him as one of my tribe. I was so looking forward to our planned download of "all the things" when he got home. I am crushed that I will never hear that story. I am crushed knowing that there are over 1,000 people in Nepal suffering this exact feeling, knowing that they too will never hear another tale about an adventure lived from someone that they love. Disasters like this are often unquantifiable, the enormity is too much to understand. Please remember that each person who is now gone was someone's Dan. Please remember that our time on this Earth is not guaranteed. Please tell those you love that you do. Right now. This very minute. And please send a kiss to the sky for my friend Dan. His energy is so big and so bright, and it's all around us, so put some love toward him today. And then hug your loved ones again. #goodbyesweetfriend #savetheice #Nepal #AdventureswithDAN

A photo posted by Sophia Bush (@sophiabush) on


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