Blake Lively, Sarah Michelle Gellar, David Boreanaz, Ed Westwick, Kim Cattrall, Kenan Thompson, Melissa Joan Hart and more shared tributes to Trachtenberg.

Kenan Thompson shared a touching tribute to his fellow Nickelodeon alum Michelle Trachtenberg, who died at age 39 on Wednesday, Feb. 26.

Comedian and former Nickelodeon child star Kenan Thompson shared a video on Instagram of the two of them on Nick, writing: “Our first Nick movie star has departed us!! She was my friend and now she rests!!” One of Trachtenberg’s first roles was in the Nick series “The Adventures of Pete & Pete.”