Blake Lively on Wednesday shared a lengthy tribute to her “Gossip Girl” costar Michelle Trachtenberg, who was found dead in her New York City apartment on Wednesday morning. Trachtenberg, also known for her roles in “Buffy the Vampire Slayer” and “Harriet the Spy,

Michelle Trachtenberg, the actress who rose to fame as a child star with films like “Harriet the Spy” and went on to have memorable roles on TV shows including “Gossip Girl,” has died, according to an NYPD source.

Actress Michelle Trachtenberg, who rose to fame as a child star in the 1990s and 2000s, has died aged 39. Police in Manhattan said they responded to an emergency call on Wednesday morning and found Trachtenberg "unconscious and unresponsive". She was pronounced dead at the scene.