Blake Lively shares a deeply personal tribute after the shocking death of Michelle Trachtenberg.

Blake Lively is mourning the loss of her Gossip Girl costar Michelle Trachtenberg, who was found dead in New York City on 23 February. The actress, 37, took to Instagram to share an emotional tribute, remembering her former colleague as a force of nature and a deeply kind soul.

Posting a photo from their time on the hit teen drama, Lively reflected on their first encounter, describing Trachtenberg as someone who “was electricity” and whose presence instantly changed a room.

“Everything she did, she did 200%,” Lively wrote. “She laughed the fullest at someone’s joke, she faced authority head-on when she felt something was wrong, she cared deeply about her work.”

Trachtenberg, best known for playing Georgina Sparks on Gossip Girl, had a career spanning decades, with notable roles in Buffy the Vampire Slayer and EuroTrip. Her portrayal of Georgina—a character both loved and loathed—made her a standout on the series, where she often clashed with Lively’s Serena van der Woodsen.

Despite their on-screen rivalry, Lively described her former costar as “fiercely loyal”, adding that she was “big and bold and distinctly herself.”

However, Lively also expressed regret at how time and life had caused them to drift apart. “You take for granted that you get the chance to see an old friend. To paraphrase, the real tragedies in life are the ones that blindside you on an idle Tuesday,” she wrote.

Her tribute ended with a heartfelt message about Trachtenberg’s impact on the world: “The world lost a deeply sensitive and good person in Michelle. May her work and her huge heart be remembered by those who were lucky enough to experience her fire.”

The cause of Trachtenberg’s death has not yet been publicly disclosed. As fans and former colleagues continue to process the loss, Lively’s tribute stands as a poignant reminder of the lasting impact Trachtenberg had on those around her.