Michelle Trachtenberg, star of the teen drama series “Gossip Girl” and “Buffy the Vampire Slayer,” has died at 39 years old, the New York Police Department confirmed to CBS News on Wednesday. She was found at her home in Manhattan, and the death is not believed to be suspicious, police said.  

The NYPD said officers responded to a 911 call at 8:01 a.m. local time Wednesday to an apartment in midtown Manhattan, where they found the actress unconscious and unresponsive.

“Criminality is not suspected. The Medical Examiner will determine the cause of death,” the police statement said, adding that the investigation is ongoing.

Through her representative, Trachtenberg’s family confirmed the actress’ death and requested privacy for their loss.  

Rosie O’Donnell told CBS News her former costar’s death was “heartbreaking.” The comedian who appeared in the 1996 “Harriet the Spy” hit movie alongside Trachtenberg said, “I loved her very much. She struggled the last few years. I wish I could have helped.”

Trachtenberg, a child actor who grew up in Brooklyn, appeared in her first commercials at age 3, according to the movie database IMDb. At 8 years old, she landed a role as Nona Mecklenberg on Nickelodeon’s “The Adventures of Pete & Pete,” which ran from 1994 to 1996. 

She starred in “Harriet the Spy” and other movies, and landed the plum role of Buffy’s younger sister, Dawn, in the hit series “Buffy the Vampire Slayer” in 2000. She wasn’t yet 18 years old. 

Years later, in 2021, Trachtenberg joined other actors from the series accusing prominent show-runner and filmmaker Joss Whedon of inappropriate behavior when they worked with him on the “Buffy” set. Actress Charisma Carpenter, who played Cordelia Chase, was the first person from the show to come forward with allegations. 

Trachtenberg said in a social media post at the time that there was a rule saying Whedon “was not allowed in a room alone with Michelle again.” In a 2022 interview, Whedon told New York Magazine he knew nothing about that, and he denied accusations of inappropriate and cruel behavior.

Trachtenberg went on to star in the hit series “Gossip Girl,” in the role of Georgina Sparks, and appeared in various other series and television movies including “House” and “NCIS: Los Angeles.”

contributed to this report.