Michelle Trachtenberg, the actor known for “Gossip Girl,” “Buffy the Vampire Slayer” and “Harriet the Spy” died Wednesday. She was 39. New York City police responding to a call at a residential high-rise building in Manhattan found Trachtenberg unresponsive and emergency medical services pronounced her dead at the scene,

Michelle Trachtenberg's cause of death was revealed Thursday after the 39-year-old actress was found dead in New York City Wednesday morning.

The cause of death for actress Michelle Trachtenberg has been ruled “undetermined” by the New York City Medical Examiner, according to an agency spokesperson.

Blake Lively on Wednesday shared a lengthy tribute to her “Gossip Girl” costar Michelle Trachtenberg, who was found dead in her New York City apartment on Wednesday morning. Trachtenberg, also known for her roles in “Buffy the Vampire Slayer” and “Harriet the Spy,

Rosie O’Donnell paid tribute to her former co-star, Michelle Trachtenberg, who was found deadin her New York City apartment on Wednesday. “Heartbreaking,” O’Donnell said in a statement to Us Weekly. “I loved her very much.

The cause and manner of Michelle Trachtenberg's death will remain undetermined, according to the New York City Office of the Chief Medical Examiner.

No cause of death has been determined for actor Michelle Trachtenberg, whose body was found on Wednesday at her Upper West Side home, according to the New York City chief medical examiner’s office.A source told NBC New York that Trachtenberg,

Michelle Trachtenberg decided to "pull back from Hollywood" after her career as a child and teen star, a source exclusively tells PEOPLE, adding that leading up to Trachtenberg's unexpected death, she was more of a "recluse" but "always kind,

Michelle Trachtenberg's cause of death remains 'undetermined' after the 'Gossip Girl' and 'Buffy' star's family objected to having an autopsy performed.

Undetermined can mean either that there was inadequate information to assess how a person died or that the information was conflicting, with equal amounts supporting or negating a specific "manner" of death,

Multiple reports say the 39-year-old ‘Gossip Girl’ star had a liver transplant in the past year, but without an autopsy her death certificate will say her cause of death is