Patrick Dempsey is mourning the loss of his friend and Grey's Anatomy costar Eric Dane.

In a UK radio interview on Friday (February 20), Dempsey shared his heartbreak after learning of Dane's death, per Page Six. The actor passed away on Thursday at the age of 53, ten months after revealing he had been diagnosed with amyotrophic lateral sclerosis (ALS).

"I just woke up this morning, and I was very sad to read the news... It's hard to put into words. I feel really sad for his children," Dempsey said, referring to Dane's daughters Billie, 15, and Georgia, 14, whom he shared with wife Rebecca Gayheart.

The Enchanted actor explained that he noticed how "rapidly" his friend's health had been declining during recent conversations and visits from other friends.

"I was corresponding with him, we were texting so I spoke to him about a week ago and some friends of ours went in to see him, and he was really starting to lose the ability to speak," he said. "He was bed-ridden and it was very hard for him to swallow, so the quality of his life was deteriorating so rapidly."

Dempsey, who starred as Derek Shepard opposite Dane's Mark Sloan for several season on Grey's Anatomy, also recalled some fond memories working together on set, noting that Dane "was the funniest man," E! News reports.

"He's such a joy to work with, and I want to just remember him in that spirit," he said. "Anytime he was on set, he brought so much fun to it. He had a great sense of humor. He was easy to work with. We got along instantly. His first scene was him in all his glory coming out of the bathroom with a towel on looking amazing, making me feel completely out of shape and insignificant."

Dempsey shared how the two actors "hit it off" while working together because they never felt competition between them.

"It was just this wonderful mutual respect," he said. "He's wickedly intelligent. I'm always going to remember those moments of fun we had together and celebrate the joy that he did bring to people's lives. The real loss is for us who don't have him anymore."

The Memory of a Killer star also praised Dane's advocacy and honesty amid his battle with ALS.

"He did an incredible job at bringing awareness to this horrible disease and those remaining days, which was really brave of him to do," he said. "It just reminds us that we all have to celebrate every day like it's our last day."

Dane's family confirmed in statement on February 19 that he had passed away "following a courageous battle with ALS," according to People.

"He spent his final days surrounded by dear friends, his devoted wife, and his two beautiful daughters, Billie and Georgia, who were the center of his world," the statement read. "Throughout his journey with ALS, Eric became a passionate advocate for awareness and research, determined to make a difference for others facing the same fight. He will be deeply missed, and lovingly remembered always. Eric adored his fans and is forever grateful for the outpouring of love and support he's received. The family has asked for privacy as they navigate this impossible time."