Bollywood famous Singer Krishnakumar Kunnath, popularly known as KK, who was in Kolkata for a concert, died on Tuesday evening (May 31) at the age of 53. The playback singer collapsed after the concert and was rushed to a private hospital in the city. PM Narendra Modi has expressed grief over the untimely sad demise of the famous singer. While talking to Aajtak, renowned singer Udit Narayan also expressed grief and said it is unbelievable and unacceptable. Watch this video.