It came as footage of Cornell performing his last ever concert emerged online as tributes poured in following sudden death of the rock legend. "Very sad. Very sad".
Cornell formed Audioslave in 2001 with former Rage Against the Machine members.
(AP Photo/Chris Pizzello, File).
With his flowing curly hair and often bare chest, Cornell showed off his vocal skills on Soundgarden hits such as "Black Hole Sun", set to dissonant minor chord progressions on guitar.
Cornell was found dead in a bathroom, hours after a concert in Detroit.
Soundgarden were due to headline a rock music festival called Pointfest in St Louis on Saturday but organisers have called off the event.
Cornell had a special connection to Australia, not because of his sell-out shows at the Sydney Opera House and Melbourne or three appearances at Big Day Out festival, but because he nearly drowned here.More news: Will Smith, Almodovar open a testy Cannes Film Festival
A full autopsy report was not yet completed Thursday afternoon.
They disbanded in 2007 - with their track record lit by three Grammy nominations. "Detroit Rock City! It's great to be back here, honestly", Cornell said after the group started the show with "Ugly Truth".
Brian Bumbery, Cornell's representative, called the singer's death "sudden and unexpected" and said his wife and family were shocked. The Detroit News cited Freeman in a similar report.
The Detroit police media relations director, Michael Woody, told The Detroit Free Press that, "Based on our observations at the scene, we are investigating it as a possible suicide", adding that, "We're not saying specifically why". 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.
Musician Chris Cornell poses at Elton John's 70th Birthday and 50-Year Songwriting Partnership with Bernie Taupin benefiting the Elton John AIDS Foundation and the UCLA Hammer Museum at RED Studios Hollywood in Los Angeles, California, March 25, 2017.
Billboard described Cornell as being in "fine form and spirits" during Soundgarden's show last night.