Kim Jong-hyun, from the hit Korean boy group SHINee, has died at 27, reportedly after committing suicide at a studio apartment in the Gangnam district of Seoul.

Better known as Jonghyun, he was one of the five members of SHINee, an extremely popular band that has had multiple chart-topping hits in its home country.

"We are sorry to share such heartbreaking and tragic news... SHINee's Jonghyun left us suddenly," said SM Entertainment, Jonghyun's management company.

Authorities say Jonghyun's death isn't being regarded as suspicious, and his relatives apparently had not requested an autopsy to be performed.

There is strong evidence of the singer's suicidal ideation: Jonghyun's sister called the police on Monday, Dec. 18, after receiving disturbing messages from him, with phrases such as "this is my last farewell," as BBC reports.

Two weeks before his death, Jonghyun also sent a message to his friend, Jang Hee-yeon, a singer from the band, Dear Cloud. He asked him to post the said message on social media if he disappears.

"I'm broken from inside. The blues that slowly ate at me has finally swallowed me whole. I couldn't overcome," the message read. "I hated myself. Holding on to disappearing memories and screaming at it to wake up. There was no answer. If I can't breathe, it's better to stop."

It's not clear whether the singer was suffering from depression, but the message above is a clear and strong indication.

After finding him unconscious in the aforementioned apartment, Jonghyun was rushed to a nearby university hospital but was declared dead later that evening, according to SM Entertainment in its statement.

SHINee is tremendously popular not only in Korea but also in other parts of the world where K-pop is a big part of the music scene. The band rose to widespread popularity with the release of its debut album, Replay, in 2008.

In addition to singing and dancing, he contributed a great deal to the songwriting aspect of SHINee's body of work. He also launched a solo career in 2015. The singer was regarded by many fans as a very shy and sensitive person who did not bask in the hedonism or unapologetic pleasure-seeking that often goes hand-in-hand with stardom.

"Apart from the time he performed, he didn't talk much most of the time... the thing he cared the most about was his singing and performance," said Fang Wang, a Chinese journalist who served as an interpreter for Jonghyun during a 2014 fan meet-and-greet.

"[Jonghyun] didn't attract as much attention as other band members when he was offstage. Quiet and reticent, he was always walking behind the others," according to another interpreter who had worked with the band in the past. "Yet during rehearsals, he came across as a lead singer. He took his singing and dancing rehearsals really seriously — you could tell he was a serious, grounded person."

The band has posted a tribute to the singer on Twitter.

Fans paid their respects at the Asan Hospital on Tuesday, Dec. 19, ahead of a private funeral that the family has requested to be held "as quietly as possible."

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