Michelle Trachtenberg, best known for her work onBuffy The Vampire SlayerandGossip Girl, has died at 39, leaving friends and former co-stars mourning her untimely death and sharing heartbreaking tributes online. Police confirmed that Trachtenberg was found deceased in her New York City apartment by her mother on Wednesday, February 26. The cause of death has not yet been revealed, though it is known she recently underwent a liver transplant.
Trachtenberg’s career began with commercials before appearing onLaw & OrderandClarissa Explains It Allwhile she was still a child. She later gained recognition in Nickelodeon’sThe Adventures of Pete & Pete,All My Children, and the 1996 filmHarriet the Spy. In 2000,she joinedBuffy the Vampire Slayeras Dawn Summers, Buffy’s younger sister, a role she played until the show’s conclusion in 2003. From 2008 to 2012, she portrayed the memorable Georgina Sparks onGossip Girl, reprising the role for the 2022-2023 revival, which marked her final on-screen appearance.

Former co-stars and friends have taken to social media and issued statements to honor Trachtenberg’s impact, both on and off-screen. Kim Cattrall, who worked with Trachtenberg onIce Princess, paid homage to the late actress on Instagram and X, expressing her sadness and calling Trachtenberg “sweet” and “talented.”
Buffy the Vampire Slayerco-star James Marsters remembered Trachtenberg as a “beautiful soul,” “fiercely intelligent,” and “howlingly funny.” Alyson Hannigan, a fellowBuffyalum, shared photos and recalled Trachtenberg’s “loving energy” on set. Emma Caulfield described the loss as like losing a “little sister” from their “Buffy family.” David Boreanaz andGossip Girlco-star Ed Westwick also offered their condolences through Instagram stories.

Melissa Gilbert, who appeared with Trachtenberg inA Holiday for Love, expressed sadness for Trachtenberg’s family. Melissa Joan Hart, who worked with Trachtenberg onClarissa Explains It All, shared a nostalgic Instagram post, remembering their early collaboration.SNL’s Kenan Thompson, a fellow former Nickelodeon child actor, also posted a tribute.
‘Harriet the Spy’ Team Remembers Michelle Trachtenberg
Largely considered her breakout role,Harriet the Spystarred a young Trachtenberg alongside Rosie O’Donnell, Vanessa Lee Chester, and Gregory Smith. In a statement to US Weekly, O’Donnell mourned the actress, sharing:
“Heartbreaking. I loved her very much. She struggled the last few years. I wish I could have helped.”

J. Smith-Cameron, who starred as Trachtenberg’s mother in the film, remembered Trachtenberg as an “excited” and “charming little girl.” In a statement shared withPEOPLE, she spoke fondly of Trachtenberg. Noting thatHarriet the Spywas Trachtenberg’s first film, she shared:
“Her natural ebullient nature was ratcheted up into giddiness as she tried to learn how to handle all that came with that. She was a very charming little girl. Years later we found each other on social media and connected briefly. She was always very warm toward me. I feel very shocked and unsettled to hear of her passing.”

Harriet the Spydirector Bronwen Hughes also spoke of Trachtenberg’s on-set energy, telling theHollywood Reporter:
“Michelle was like a lightning bolt of a casting discovery. She had fire, she had spark, she had truth, and she had Harriet’s conviction, like her sense of self. No one else came in the room like that. So she had that acting gene that you may’t really teach. It’s innate, which is not something you find very often.” He added: “She was everything that Harriet needed to be, and she never had a false note, and you couldn’t really take your eyes off her. That was magical casting for us.”