Michelle Trachtenberg, a former child star who appeared in the 1996 "Harriet the Spy" hit movie and went on to co-star in two buzzy millennial-era TV shows — "Buffy the Vampire Slayer" and "Gossip Girl" — has died.

Police officers, responding to a 911 call, found her unresponsive in a Manhattan apartment on Wednesday morning, the authorities said.

In a statement, NYPD said that officers responded to a 911 call just after 8 a.m. and Trachtenberg was pronounced dead by emergency medical workers, who also responded to the scene.