As news of Luke Perry's tragic death spread on Monday, his current and former co-stars took to social media to pay their respects.
The actor, who was 52, shot to fame playing bad-boy heartthrob Dylan McKay on "Beverly Hills, 90210" in the 1990s.
More recently, he was one of the stars of The CW's critically lauded "Riverdale" series, playing Fred Andrews, father of Archie Andrews.
Shannen Doherty told People magazine that she'd met up with him February for lunch, with Perry choosing a restaurant that would accommodate his dog. "I walked in and there he was, smiling," she said. "I will never forget — and will miss — Luke looking at me with that smile of his saying, 'Shan.'"
"Luke was a smart, quiet, humble and complex man with a heart of gold and a never-ending well of integrity and love," she added, noting that Perry had connected with her while she battled breast cancer (she's now in remission). "I will miss him every day. Every minute. Every second."
Co-star Tori Spelling also spoke with People magazine. "I'm in utter shock and heartbroken," she said. "Luke was one of the kindest and most humble human beings I've ever known... He truly was family to me, a protector and a brother."
Gabrielle Carteris joined other "90210" co-stars in expressing condolences and sharing heartfelt memories of Perry.
"I am absolutely heartbroken," she said in a statement. "Luke was a tremendous force in the lives of so many. He was a very sensitive soul who was kind, generous and he fought for the underdog. He was a strong voice and an advocate who will be so missed by all who knew him. He has left his mark — never to be forgotten. My heart goes out to his family, friends and fans around the globe."
In a statement to People, Jennie Garth said, "My heart is broken. He meant so much to so many. Such a very special person. I share my deep sadness with his family and all who loved him. Such a terrible loss."
Ian Ziering posted a tribute to Instagram.
"Dearest Luke, I will forever bask in the loving memories we've shared over the last thirty years. May your journey forward be enriched by the magnificent souls who have passed before you, just like you have done here for those you leave behind. God please give him a seat close to you, he deserves it," he wrote.
Rebecca Gayheart, whose "90210" character, Toni, was a love interest of Perry's Dylan, wrote that she was "just heartbroken."
Actress Christine Elise, who played Emily Valentine on "90210," shared a photo of herself with Perry and co-star Jason Priestley.
"With the heaviest of hearts, I am stunned and devastated to tell you that Luke passed away. I am still in shock and I have no words beyond saying he was a truly kind gentleman. He will be mourned and missed by everyone who knew him and the millions who love him. RIP, dearie Luke. Your time here was far too short," she wrote.
Emma Caulfield Ford, who filled the role of Susan Keats on the prime-time drama in the mid-'90s, wrote that she was "heart sick" over the loss of Perry, calling him an "angel and a friend."
Paul Johansson, who had a recurring role as John Sears, wrote, "You will be missed dear friend. My heart is broken."
"My heart is broken. I will miss you so much Luke Perry. Sending all my love to your family," wrote actress Molly Ringwald, who currently plays Perry's wife on The CW series "Riverdale."
Carol Potter, who played Brandon and Brenda's mom Cindy, called Perry's death "unfathomable."
Stephanie Beacham played Dylan's mom Iris in a recurring role and wrote that she was "devastated that my 'son' Luke has gone. Far too young."
Kathleen Robertson joined the show in its second half to play one of the young adults hanging out with the core gang as Clare Arnold, and noted how she'd been a fan first: "Luke welcomed me from day one."
The writers of "Riverdale" called Perry "a joyful and vibrant soul."
"You will be missed but most certainly your legacy will be remembered forever. Rest in love and peace, friend," they tweeted.
Actress Camilla Mendes, who plays Veronica Lodge on "Riverdale" wrote on Instagram that Perry was "an authentic man who took pleasure in offering us his guidance and wisdom" and "had the ability to make you feel comfortable and at ease within seconds of seeing him."
And actor KJ Apa, Perry's on-screen son, Archie Andrews, in the CW drama, offered a simple tribute on Instagram.