The actress played socialite Georgina Sparks on the hit CW series Michelle Trachtenberg’s Gossip Girl costars, Ed Westwick and Chace Crawford, are paying tribute to her after her sudden death at age 39.

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.

Blake Lively, Sarah Michelle Gellar, David Boreanaz, Ed Westwick, Kim Cattrall, Kenan Thompson, Melissa Joan Hart and more shared tributes to Trachtenberg.