Cornell was found at the MGM Grand Detroit hotel by a family friend who had been asked by the rock star's wife to check on him. The Wayne County Medical Examiner has confirmed the cause of death as suicide by hanging.
Cornell referenced death - and suicide - in 2007 interview with the AP when discussing his single, "No Such Thing".
The musician, who was also a skilled songwriter, had tweeted a picture of the music venue shortly before the sold-out show, writing: "Finally back to Rock City!".
He said Cornell wife and family were shocked by it.
Soundgarden were one of the leading bands in the grunge music movement in the 1980s and '90s, releasing albums such as Badmotorfinger and the Grammy-winning Superunknown, which brought the band mainstream success.
He formed Soundgarden in 1984 in the city along with guitarist Kim Thayil and bass player Hiro Yamamoto.
"In my time of dying, I want nobody to mourn/All I want for you to do is take my body home", the song says.
Even without the benefit of hindsight from the morning's terrible news, it was clear that something wasn't right with the 52-year-old Cornell during the Fox performance.
"You may think Cornell's life has come to an end, but thanks to the work of a special friend, an unexpected twist concludes the clip". Cornell was roommates with Andrew Wood, lead singer of the Mother Love Bone, who died of a heroin overdose in 1990.
After the band broke up in 1997, Cornell pursued a solo career - though only for a few years.
Very sad news about Chris Cornell today.