News of Michelle Trachtenberg's death prompted tributes from her friends and former "Buffy," "Harriet the Spy," and "Gossip Girl" costars.

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, whose career broke out in childhood with “Harriet the Spy” and went on to include “Buffy the Vampire Slayer” and “Gossip Girl” has been found dead in her Manhattan apartment,