Kim Jonghyun, the lead vocalist of Korean boy group SHINee, has died at the age of 27.

After rumors of his sudden death erupted on Monday night, SM Entertainment, the musician's talent agency, confirmed that Kim was found unconscious at a hotel in Seoul, and died at the hospital. Police say the reason for his death was suicide.

Reports say Kim texted his sister before the incident, hinting that he was going to take his life. This prompted his sister to run to his hotel, but it was too late.

On Tuesday, musician Nine from the modern rock band Dear Cloud, released a note apparently handed to her by Kim two weeks before his death. In the letter, Kim explained his reason for taking his life, hinting that the pressure of the entertainment industry was the problem.

"The life of fame was never meant for me. That's all the reason why it hurts. Because I'm famous. Why did I choose this. It's so funny. It's a wonder I lasted so long," he said in the translated note.

Kim added that he felt "alone" in the world, knowing exactly what was wrong with him, but not being able to do anything about it.

Kim's family is holding a three-day funeral for the singer at Asan Medical Center in Seoul. According to Metro, at least 500 fans queued to mourn Kim with flowers and photographs.

The family, however, requested for the main funeral to be held on Dec. 21 to be a "quiet" affair. It will be led by the remaining four members of SHINee -- Choi Minho, Lee Taemin, Onew (Lee Jin-ki), and Key (Kim Ki-bum) -- who will play the role of chief mourners, a task usually given only to family members.

Several personalities have also visited the funeral to pay their respects to the late singer. SM Entertainment founder Lee Soo Man, BoA (Kwon Bo-ah), SNSD's Kwon Yu-ri and Im Yoon-ah, as well as boy groups EXO, BTS, and NCT are some of them.