Key Takeaways:

• Michelle Trachtenberg was found dead at her Manhattan apartment at the age of 39.
• Her cause of death remains under investigation with early indications of natural causes following recent health struggles.
• Fellow actors, including Sarah Michelle Gellar and Blake Lively, have expressed their condolences and shared heartfelt memories.

Michelle Trachtenberg, the beloved actress known for her roles in Buffy the Vampire Slayer and Gossip Girl, has tragically passed away at the age of 39. New York police responded to a 911 call on February 26, where they discovered her unresponsive in her luxury Midtown Manhattan apartment. Though there are currently no indications of foul play, the New York Medical Examiner is investigating the circumstances and cause of her death, which may relate to complications from a recent liver transplant, according to early reports from LATimes.

Trachtenberg began her career as a child actress, achieving fame with her role as Harriet in the 1996 film Harriet the Spy. She later became a household name for her portrayal of Dawn Summers in Buffy the Vampire Slayer from 2000 to 2003, and as the notoriously villainous Georgina Sparks in Gossip Girl from 2007 to 2012. Her co-star Sarah Michelle Gellar shared a touching tribute on Instagram, writing, "Michelle, listen to me. Listen. I love you. I will always love you. The hardest thing in this world, is to live in it." This sentiment was echoed by fellow cast members such as Alyson Hannigan and James Marsters, who highlighted Trachtenberg's vibrant spirit and sense of humor, calling her "a beautiful soul" and "fiercely intelligent".

Others from the entertainment industry have voiced their heartache over her death. Blake Lively, who co-starred with Trachtenberg in Gossip Girl, described her as "electricity," and noted that "the world lost a deeply sensitive and good person." Rosie O'Donnell, who featured alongside Trachtenberg in her debut film, expressed her sorrow by emphasizing the struggles the actress faced in recent years, saying, "I loved her very much... I wish I could have helped."

The Hollywood community has come together in grief, celebrating Trachtenberg's talent and kindness, as they reflect on the impact she made both on- and off-screen. The investigation into her passing continues, and her family has requested privacy as they mourn this immense loss. For more on the reactions and tributes, visit HuffPost.