SEATTLE -- Grief-stricken Chris Cornell fans left flowers at memorials across Seattle for the musician whose forceful, sombre songs helped cement the city's place in rock history.

One of the locations where people gathered was the Sound Garden art sculpture at a Seattle park, for which Cornell's band Soundgarden was named.

"It's really sad that he could never find peace in his life," said Chad White, who came to the art display with his young son Ignatius to honour Cornell.

A bench near the centre of the sculpture was covered with flower arrangements, one of which included a note, "Say 'hello' to Heaven," a reference to a song written by Cornell for a musician friend who died decades ago.

KEXP, Seattle's popular independent radio station, paid tribute to Cornell all day. The station played non-stop songs from Soundgarden, Cornell's other bands and his solo work, as well as artists who covered Cornell's material and those who were influenced by him.

"Seattle's son, Chris Cornell, has passed away," DJ John Richards told listeners.

The city's Space Needle went dark at 9 p.m. for an hour in tribute to Cornell.

Cornell was born and raised in the city and was part of a close-knit group of artists who formed the foundation of what would become the grunge scene that exploded in the early 1990s by combining the bombast of early 1970s heavy metal with the aggression and attitude of punk rock.

"He was a huge influence, one of the greatest singers ever to come out of Seattle, maybe the greatest single voice," said Charles R. Cross, a Seattle-based music journalist and author who knew Cornell personally.

"I don't even know what to say. I'm just shocked," he said. "We don't know the full story. The darkness I knew. But it's a devastating loss."

Authorities say Cornell hanged himself in a Detroit hotel room Wednesday following a Soundgarden concert. The band had reunited in 2010 after years on hiatus.

The group formed in Seattle in the 1980s at a time when the city was far off the beaten path of the musical mainstream and there were few venues for smaller artists to play original material.

Cornell was roommates with Andrew Wood, lead singer of the Mother Love Bone, who died of a heroin overdose in 1990. Two members of Mother Love Bone went on to form Pearl Jam and they joined Cornell on a tribute project to Wood -- Temple of the Dog -- which helped introduce Pearl Jam singer Eddie Vedder to the world.

Soundgarden, Pearl Jam, Alice in Chains and Mudhoney were among the most high-profile bands to come out of Seattle and dominated the pop culture landscape of the early and mid-1990s.

"In some ways, they (Soundgarden) were the last band in Seattle to become famous in the grunge era but they were the ones who worked the hardest and the longest," Cross said. "There's no doubt that Soundgarden's music is very dark and melancholy at times. There are also parts of it that are very celebratory."

Associated Press reporter Phuong Le and photographer Elaine Thompson contributed to this report.