Michelle Trachtenberg’s death at just 39 years old has shocked both her fans and former collaborators. But those who encountered her in her final days say the signs were there that something was very wrong.

Blake Lively paid tribute to her Gossip Girl costar Michelle Trachtenberg. Yesterday, news emerged that the actor had died at age 39. Though her cause of death is still unknown, police sources noted that she recently underwent a liver transplant.

Actress Michelle Trachtenberg, known for roles in "Buffy," "Harriet the Spy" and "Gossip Girl" was found dead in New York City Wednesday at age 39.