Jonghyun, a member of South Korean band SHINee, performs during a 2012 concert in Hong Kong. (Kin Cheung/AP)

Kim Jong-hyun, the lead singer of the South Korean boy band SHINee, died Monday in what police are calling a possible suicide, devastating fans of the megastar best known by his stage name, Jonghyun.

SHINee's record label, SM Entertainment, confirmed the 27-year-old singer’s death in a statement Monday.

“We are sorry to deliver such heartbreaking and unfortunate news,” the statement read. “On December 18, SHINee member Jonghyun suddenly left us.”

The record label added that its employees and fellow SM artists were deeply shocked and grieving.

“Jonghyun was the best artist who loved music more than anyone and gave his all on the stage,” the statement said. “It is heartbreaking to deliver such sad news to the fans who loved him.”

The performer was found unconscious Monday afternoon at his residential hotel in Cheongdam-dong, a high-end enclave of the Gangnam District in Seoul, and rushed to a nearby hospital, where he was later declared dead, the SM statement said.

Jonghyun’s sister told police she received foreboding text messages from her brother alluding to a “final farewell” and called emergency responders late Monday afternoon because she feared Jonghyun was going to take his own life, according to the Yonhap News Agency.

Police have not yet ruled the death a suicide and an autopsy will be conducted, local news outlets reported.

The five-member SHINee boy band broke onto the Korean music scene in 2008, and Jonghyun shot to fame for his varied, emotive vocals and stage presence. He later also developed a successful solo career, frequently collaborating with other artists and making appearances on shows such as “Saturday Night Live Korea.”

“SHINee was a really innovative boy band, and they really represented how K-pop is this very innovative, boundary-less music scene,” K-pop expert Jeff Benjamin told The Washington Post. “Jonghyun debuted as a teenager, and I think a lot of people felt like they grew up with him.”

Benjamin, an editor at Fuse TV who has also been a K-pop columnist for Billboard for five years, said he came to appreciate Jonghyun’s thoughtful approach to musicmaking, as well as his signature way of singing. (“He has this belt that just sort of gives you chills automatically,” he said.)

However, Benjamin hesitated to compare SHINee with an American boy band because, unlike a lot of U.S. groups, SHINee has maintained relevancy and strong record sales for nearly a decade.

“Our boy bands tend to maybe not age so gracefully,” Benjamin said. “[SHINee was] still just as hot as they were.”

Hundreds of fans of the K-Pop band SHINee paid their respects to lead singer Kim Jong-hyun who died in an apparent suicide in Seoul on Dec. 18. (Reuters)

Also rare was the group’s cohesion. Since SHINee’s inception, no one had left the band and there was never any public drama. Benjamin said he asked Jonghyun about that when they last spoke earlier this year at KCon in Los Angeles.

“He actually specifically talked about the importance of giving each other physical and emotional space,” Benjamin said. “Despite the circumstances of how he may have passed, which we still need to wait for the autopsy report, it sounds like he was very much thinking about mental health and how to best navigate that or survive.”

The singer’s death stunned fans around the globe and shed light on the singer’s struggles with mental health. As news spread, SHINee fans — who call themselves “Shawols,” an amalgam of the band name and “world” — first responded with skepticism and disbelief. Though the band had enjoyed immense popularity in South Korea and elsewhere, they had just earlier this year made their first tour stops in the United States, playing full-length concerts in Dallas and Los Angeles in March.

After SM Entertainment released its statement Monday confirming Jonghyun’s death, tributes to the singer poured forth from “devastated” fans and fellow artists. Even in the United States, Jonghyun and SHINee were trending on Twitter, and remembrances often intersected with another trending hashtag, #MyMentalHealthIn5Words.

Fans also pointed to Jonghyun’s final Instagram post, made on Nov. 20, that included a screen image of song lyrics from “Beside You,” a song by another K-pop group named Dear Cloud:

Crouched my body in a dark room and thought to myself

Will you one day regret letting go of everything

Will the constant wounds and exhausted sighs come to a stop

I pray you are no longer in pain

All I wish is for you to be happy

Please don’t stay in darkness alone

Don’t torture yourself

Don’t torture yourself

Please

Below the image, Jonghyun captioned the post with a single line: “I pray you are no longer in pain.”

네가 아파하지 않길 기도해

A post shared by @ jonghyun.948 on

Michelle Ye Hee Lee contributed to this report.