Princess Eugenie is mourning the loss of her “special friend,” actor Michelle Trachtenberg. The royal posted a moving tribute to the late actor on her Instagram Story this week. Trachtenberg, 39, was confirmed dead on Wednesday after her mother discovered her in her New York City apartment.

Michelle Trachtenberg’s former costars are paying tribute to her in the wake of her sudden passing. Trachtenberg has died at 39 years old, Deadline reported today. The New York Police Department responded to a 911 call on Wednesday morning,

Eugenie became friends with Trachtenberg when she lived in New York City and worked for the art auction start-up Paddle8 from 2013 to 2015. Their friendship first became public in December 2013, when they were photographed courtside at a Knicks game alongside actor Michael K.