"Sending prayers," the actor behind Chuck Bass wrote.Ed Westwick is mourning the death of his Gossip Girl costar Michelle Trachtenberg.Westwick, who played the sleazy Chuck Bass on the CW show for six seasons,

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.