Blake Lively is mourning her "fiercely loyal" and "brave" Gossip Girl costar Michelle Trachtenberg after her death at age 39.

Blake Lively, who co-starred with Michelle Trachtenberg on the teen drama "Gossip Girl," paid tribute to the late actress on ...

Blake Lively broke her social media silence on Wednesday to pay tribute to her late “Gossip Girl” co-star Michelle ...

Blake Lively, Rosie O'Donnell and other Hollywood figures are paying tribute to Michelle Trachtenberg, who died at 39.

Blake Lively took to her Instagram Stories Wednesday evening to share a lengthy tribute to her "Gossip Girl" costar Michelle ...

Gossip Girl star Blake Lively has shared a poignant tribute to her late co-star Michelle Trachtenberg, who passed away ...

Lively shared a photo of the day she met Trachtenberg, writing, "The world lost a deeply sensitive and good person" ...

Michelle Trachtenberg's 'Gossip Girl' co-star Blake Lively posted a tribute to the actress after news of her death.

Michelle Trachtenberg's death Wednesday left her former co-stars like Blake Lively, Rosie O'Donnell, Melissa Gilbert and ...

The “Buffy the Vampire Slayer” star was found dead in her New York City apartment on Wednesday after going into cardiac arrest.

Michelle Trachtenberg, the actor known for “Gossip Girl,” “Buffy the Vampire Slayer” and “Harriet the Spy” died Wednesday.

Michelle Trachtenberg was not interested in wading into the legal waters surrounding her Gossip Girl costar Blake Lively in ...