The late Kristoff St. John's fiancee, model Kseniya Mikhaleva, is mourning the sudden death of the actor.
The Young and the Restless star's attorney, Mark Geragos, confirmed St. John's death to ET on Monday. The cause of death is currently unknown. He was 52 years old.
Mikhaleva and St. John had been engaged since last August. On Monday, she shared a picture of him kissing her on the head on Instagram.
"How did it happen??? How??? Why did you leave so early????" she wrote. "And left me alone ..... I can’t believe ... you were everything to me .... you were a loving father, a loving man,.....how ...love?? We should doing a lot of things in future......."
She also wrote on her Instagram Story, "Why you are leave so early???? Why ... you are always in my heart."
Mikhaleva and St. John announced their engagement on Instagram last fall.
"💍❤️ special day 31.08.2018," she wrote next to close-up of her ring.