Michelle Trachtenberg, best known for starring in Gossip Girl, tragically passed away on Wednesday at the age of 39. According to ABC, her body was discovered by her mother in an apartment near Columbus Circle in New York City.

She gained fame for various film and television roles throughout the late ’90s and early 2000s, including her iconic role in Gossip Girl and her appearance in the movie Eurotrip.

Police sources, speaking to the New York Post, have stated that the cause of her death is currently unknown, though it is not being investigated as suspicious.

ABC reports that Trachtenberg had recently undergone a liver transplant.

An autopsy will be performed to determine the exact cause of death.