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

Michelle Trachtenberg’s former “Buffy the Vampire Slayer” costar Sarah Michelle Gellar is looking back at their time together ...

Gellar's tribute to her late costar echoes a monologue she delivered in the supernatural drama's season 5 finale.

Many other celebrities and co-workers of Trachtenberg’s have written tributes after the actress’s death, including her Gossip ...

Nicholas Brendon, Alyson Hannigan, David Boreanaz, and others paid tribute to their former costar after her tragic passing on ...

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

Sarah Michelle Gellar is paying tribute to her late "Buffy the Vampire Slayer" co-star Michelle Trachtenberg after her tragic ...

Cast members of "Buffy the Vampire Slayer," "Gossip Girl" and more are remembering their co-star Michelle Trachtenberg​ after ...

Fans and friends alike are mourning the loss of Michelle Trachtenberg, who died this week at age 39. Sarah Michelle Gellar ...

Sarah Michelle Gellar is paying tribute to her former costar. After Michelle Trachtenberg’s tragic death on Wednesday at age 39, the “Buffy the Vampire Slayer” alum shared a heartfelt message.

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

Blake Lively, Sarah Michelle Gellar and other Hollywood figures are paying tribute to Michelle Trachtenberg, who died at 39.