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

Actress Michelle Trachtenberg, who rose to fame as a child star in the 1990s and 2000s, has died aged 39. Police in Manhattan ...

Michelle Trachtenberg's co-stars and fellow celebrities are speaking out after the "Gossip Girl" and "Harriet the Spy" star ...

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

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.

The actress posted an emotional tribute to Michelle Trachtenberg following her shocking death at 39. Other co-stars followed ...

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, the actor best known for "Gossip Girl," "Ice Princess" and "Buffy the Vampire Slayer," died at age 39.

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