The actress played socialite Georgina Sparks on the hit CW series Michelle Trachtenberg’s Gossip Girl costar, Ed Westwick, is paying tribute to her after her sudden death at age 39. Trachtenberg — who played socialite Georgina Sparks on the hit CW series — was found dead on Wednesday,

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

From Ed Westwick to David Boreanzaz, how the casts of Gossip Girl, Buffy, and more are paying tribute to Michelle Trachtenberg.