Trachtenberg had a decades-long career, starring in a slew of iconic roles, including Dawn Summers on “Buffy the Vampire Slayer,” Georgina Sparks on “Gossip Girl,” and Casey Carlyle in the 2005 film “Ice Princess.” Most notably, perhaps, she starred in 1996’s “Harriet the Spy” alongside Rosie O’Donnell.

Michelle Trachtenburg's cause and manner of death have officially been released. The Office of Chief Medical Examiner in New York City, where Trachtenberg was found dead early Wednesday, ruled both the cause and manner of death as undetermined,