Sophia Bush 2015 - "One Tree Hill" actress Sophia Bush is currently facing a great deal of pain and loss after her 33-year-old ex-boyfriend Dan Fredinburg was killed in Nepal Sunday. Fredinburg, who dated Bush for 10 months before their breakup in Aug. 2014, was among the casualties in the massive Nepal earthquake, which triggered an avalanche in Mount Everest.

A Google Inc. engineer and Sophia Bush's ex-beau, Dan Fredinburg, was in Nepal to climb the Mount Everest. However, he was caught in an avalanche after the earthquake and suffered a "major head injury," which was the cause of his death, Wall Street Journal reported.

The death of Sophia Bush's ex-boyfriend was confirmed through a blog post by Google's privacy unit, Lawrence You. According to The Guardian, Dan Fredinburg's sister Megan also posted a message on Instagram announcing Dan's death.

"Sadly, we lost one of our own in this tragedy. +Dan Fredinburg a long-time member of the Privacy organization in Mountain View, was in Nepal with three other Googlers, hiking Mount Everest," You wrote. "He has passed away. The other three Googlers with him are safe and we are working to get them home quickly."

While Fredinburg's sister also wrote an emotional message on her brother's Instagram account confirming his death.

"This is Dan's little sister Megan," she wrote, as Washington Post quoted. "I regret to inform all who loved him that during the avalanche on Everest early this morning our Dan suffered from a major head injury and didn't make it..."

Meanwhile, Fredinburg's 32-year-old ex-girlfriend Sophia Bush also posted an Instagram message expressing her condolences after learning that Dan had died. And despite their split, Us Weekly reported that the exes remain amicable and close to each other.

"There are no adequate words," Sophia Bush wrote. "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..."

"He was one of my favorite human beings on Earth," she continued. "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..."

Sophia Bush and Dan Fredinburg were also going to reunite after his Mount Everest journey.

"I was so looking forward to our planned download of "all the things" when he got home," she posted on Instagram. "I am crushed that I will never hear that story."

Aside from Sophia Bush's ex-boyfriend Dan Fredinburg, there are also almost 2,000 people who were killed by the Nepal earthquake, as previously reported. As the quake wrecked houses, flattened centuries-old temples and triggered avalanches on Mount Everest, Nepalese officials continually monitor the casualties as death toll rises.