"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".
Police say Cornell's wife called a family friend and asked him to check on his well-being.
KEXP, Seattle's popular independent radio station, paid tribute to Cornell all day.
Chris Cornell, lead singer of Soundgarden, has died.
Soundgarden had one of the heaviest sounds in grunge with trappings of heavy metal, even though Cornell cited The Beatles, to whom he listened constantly as a child, as his biggest influence.
In interviews, Cornell discussed his past struggles with alcohol and the impact of his friends' deaths from substance abuse.
Cornell's publicist Brian Bumbery earlier called the death "sudden and unexpected" and said his wife and family were shocked by it.More news: Cold War Nuclear Explosions Freakishly Impacted Space Weather
Soundgarden was to headline Friday at Rock on the Range, a three-day concert in Columbus, Ohio.
Chris Cornell at a Soundgarden concert in Switzerland. So far a full autopsy has not yet been completed, however it has been confirmed by the Wayne County Medical Examiner that the cause of the death was by hanging. According to officials, Cornell was discovered shortly after midnight at the MGM Grand Detroit.
The 52-year-old Cornell was on tour and performed Wednesday night in Detroit with Soundgarden.
Born and raised in Seattle, Washington, Cornell was one of the main movers and shakers of the grunge movement, forming Soundgarden with guitarist Kim Thayil and bassist Hiro Yamamoto in 1984.
This particular song may not be the first song of the singer's that we think of (I'd argue that honor goes to "Black Hole Sun" or "Spoonman"), but it absolutely carries the signature of Cornell: rocking, rollicking, and bursting with energy.
Cornell also collaborated with members of what would become Pearl Jam to form Temple of the Dog, which produced a self-titled album in 1991 in tribute to friend Andrew Wood, former frontman of Mother Love Bone.
He also released solo albums, and Nielsen Music said as a band member and solo act, the singer sold nearly 15 million albums and 8.8 million digital songs in the U.S. After the band chose to break up in 1997, Cornell pursued a short-lived but well-appreciated a solo career which led up to the 2001 birth of Audioslave which consisted of Cornell and several members of the equally as legendary rock band Rage Against The Machine. And true to his ideals rooted in the grunge era, he said he would donate his proceeds from his song The Promise (for the 2017 movie of the same name) to the International Rescue Committee, which helps refugees to rebuild their lives.