The death of Michelle Trachtenberg one week ago was definitely a shock, and tributes to the late actress have ben rolling in from the Buffy cast and more. While her passing was a surprise, Trachtenberg’s friends recently opened up about the health issues she'd be not-so-privately dealing with.

More details about Michelle Trachtenberg's final days continue to emerge, with a former colleague sharing her plans before her tragic passing.

Michelle Trachtenberg’s producing partner, Casey Tebo, shared his final conversation with the “Gossip Girl” star before her shocking death.

Michelle Trachtenberg was set to make upcoming appearance at a benefit screening of her last film, 'Spyral', at the SXSW festival on March 12 before her death. Jennifer Hutchins, the producer of the film,

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.

Last week, actress Michelle Trachtenberg, best known for projects such as Harriet the Spy, Ice Princess, Buffy the Vampire Slayer,

Mitzi Gaynor, Olivia Hussey, Bernard Hill, Silvia Pinal and Alain Delon were also among the big names missing from the somber section.

Academy Awards took place Sunday in Los Angeles, where several late movie stars were remembered by their grieving peers.

Michelle Trachtenberg's cause of death was ruled "undetermined" by the Office of Chief Medical Examiner in New York City, Fox News Digital confirmed.