Rosie O’Donnell paid tribute to her former co-star, Michelle Trachtenberg, who was found dead in her New York City apartment on Wednesday. “Heartbreaking,” O’Donnell said in a statement to Us Weekly. “I loved her very much.”

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.”