The friend apparently forced open the hotel room's door and found the singer unconscious. "We are investigating it as a possible suicide, but we need to wait on the medical examiner to determine the cause and manner of death".
"A full autopsy report has not yet been completed", adds a statement. Police found his body on the floor of his hotel room's bathroom in the early morning hours after the concert. The lead singer of Soundgarden was 52-years-old when he took his own life.
Bumbery called the death "sudden and unexpected" and said his wife and family were shocked by it.
Chris Cornell's cause of death has been revealed as suicide by hanging.
The Seattle-born Cornell co-founded Soundgarden 1984 as part of the burgeoning Pacific Northwest grunge rock scene and fronted the band through six studio albums and a pair of Grammy Awards.
Our thoughts and prayers go out to Chris's family and friends.
Chris Cornell, the unmistakable voice and frontman of the bands Soundgarden and Audioslave, died overnight in Detroit at the age of 52. "It was just time for a break", he said. From 2001 to 2007, he was the lead singer of Audioslave, which consisted of Rage Against the Machine members after their lead singer, Zack de la Rocha, left in 2000, and he reunited with Soundgarden in 2011. An autopsy is being conducted Thursday and some information from it is expected to be released later in the day, Wayne County spokeswoman Lisa Croff said.
Cornell also had an extensive solo career as a singer, songwriter, guitarist, composer and lyricist and worked with various other musicians over three decades in the music business.
Cornell had spoken openly in interviews of his struggles with drugs as a teenager, and later with alcohol.
Around the time of his Timbaland produced album "Scream", Cornell covered the Michael Jackson song "Billie Jean" in an acoustic rendition that would garner him many accolades, and proved particularly powerful when Jackson died in June of 2009.
Aerosmith guitarist Joe Perry also paid tribute, writing: "Very sad news about Chris Cornell today".