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 ...

Sarah Michelle Gellar is paying tribute to her “Buffy” sister, Michelle Trachtenberg, who died on Feb. 26 at 39 years old.

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

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

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

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

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

Sarah Michelle Gellar and Michelle Trachtenberg starred in three seasons of "Buffy the Vampire Slayer" together and remained ...

Blake Lively, Sarah Michelle Gellar and others who worked with Michelle Trachtenberg remembered the “loving” and “electric” ...

Sarah Michelle Gellar played Michelle Trachtenberg’s older sister on Buffy the Vampire Slayer for seven seasons, and their ...

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