The singer, whose band The Pretty Reckless was the opening act for Soundgarden's tour, wrote on Instagram on Friday, "My heart is broken. Still in a state of shock. I have no words right now except my heart pours out to his beautiful family and friends."
The 52-year-old Soundgarden and Audioslave frontman was found dead in his hotel room at the MGM Grand in Detroit. His cause of death was determined to be suicide by hanging, and came to a shock to his family and friends.
"Chris’s death is a loss that escapes words and has created an emptiness in my heart that will never be filled," Vicky Karayiannis, who married Cornell in 2004, said in a statement to ET. "He was my best friend. His world revolved around his family first and of course, his music, second."