Sarah Michelle Gellar mourned the death of “Buffy the Vampire Slayer" co-star Michelle Trachtenberg in an Instagram post.

Trachtenberg, who co-starred with Gellar on the hit TV series, was found dead in her apartment on Tuesday. She was 39.

Sarah Michelle Gellar has paid tribute to her former Buffy The Vampire Slayer co-star Michelle Trachtenberg following her ...

Gellar is honoring her late 'Buffy the Vampire Slayer' costar, who died on Wednesday, February 26, with a powerful quote from ...

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

News of Michelle Trachtenberg's death prompted tributes from her friends and former "Buffy," "Harriet the Spy," and "Gossip ...

Sarah Michelle Gellar paid tribute to the late Michelle Trachtenberg after the actress died at age 39. "'Michelle, listen to ...

Sarah Michelle Gellar, Taylor Momsen and Blake Lively are among those paying tribute to Michelle Trachtenberg, who died ...

Sarah Michelle Gellar has poured her heart out in a gut-wrenching tribute to her "Buffy the Vampire Slayer" costar Michelle ...

Michelle Trachtenberg's former "Buffy the Vampire Slayer" costar Sarah Michelle Gellar is looking back at their time together ...

Buffy 's Sarah Michelle Gellar has paid an emotional tribute to co-star Michelle Trachtenberg, who passed away at the age of 39. Gellar took to her Instagram to share pictures of her and Trachtenberg ...

Many other celebrities and co-workers of Trachtenberg’s have written tributes after the actress’s death, including her Gossip Girl co-star Blake Lively. She shared a picture of the duo on set of the ...