Michelle Trachtenberg's death at 39, which definitely took the public by surprise. Celebrity tributes to Trachtenberg have been rolling in, and her Gossip Girl stars like Blake Lively and Chace Crawford (among others) have shared their love for her on social media.

Michelle Trachtenberg's former co-stars from “Gossip Girl” and "Buffy the Vampire Slayer" paid tribute to the actress following her untimely passing on Wednesday.

Lively shared a photo of the day she met Trachtenberg, writing, "The world lost a deeply sensitive and good person"