The Gossip Girl family is mourning Michelle Trachtenberg. Chace Crawford, who played Nate Archibald on the CW show, posted a tribute to the late actress, who was found dead in her apartment Wednesday morning.

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.

Following the tragedy, Gossip Girl alumni—including Blake Lively, Chace Crawford, and Ed Westwick—paid tribute to Trachtenberg, recalling sweet memories of their time spent on set together and how the actress made a lasting impression on them with her fiery spirit.