“Buffy” and “Gossip Girl” actress Michelle Tratchenberg died at 39

Michel Tratchenberg, best known for her roles in “Buffy the Vampire Slayer” and “Gossip Girl,” passed away at the age of 39.

Trachtenberg said his mother was found Wednesday in an apartment in New York City near Columbus Circle just after 8am local time, police sources told ABC News.

Sources told ABC News that the actress had recently undergone a liver transplant and may have experienced complications. Trachtenberg is believed to have died of natural causes and foul play is not suspected.

An autopsy will be conducted by the medical inspector's office to determine the cause and method of death.

New York City native Trachtenberg made her acting debut as a child star who played roles in the Nickelodeon Project, including the television series The Adventure of Pete. & Pete and the film “Harriet the Spy.”

Her big break came in 2000-2003 when she was cast in Buffy the Vampire Slayer as Dawn, the younger sister of Sarah Michel Guerard's honorable character.

Trachtenberg recently recalls the day he was co-starring with Gellar on “Buffy.” Last month, she shared those photos together, saying, “I killed them all day! I've always loved these twin photos!

The actress also made a cameo in a Fall Out Boy music video in 2007 for the band's hit song “This aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Trachtenberg starred in “Gossip Girl” from 2008 to 2012 with Georgina sparking. For her role, she was nominated for The Choice TV Villain at the Teen Choice Award in 2012.

“When you're saying something evil, it's a bit easy to become evil,” said Tranchenberg of her “gossip girl” role 17 2009.

Trachtenberg has also appeared in a wide range of television shows, including “Mercy,” “Weeds,” and her career, “Truth or Scare.”

In the film, she took on roles such as “Eurotrip,” “17 Again,” and “The Scribbler.”