Bollywood singer Krishnakumar Kunnath, famous as KK, dies at the age of 53 on Tuesday after falling ill while at an event in Kolkata. He was rushed to the CMRI hospital, where he was declared dead.

The singer, who has several hits to his name, was performing at Nazrul Mancha for Gurudas College’s fest when he collapsed. He suffered a massive heart attack, Times of India reported. However, there has been no official confirmation on the cause of death.

KK’s official Instagram page had visuals of a concert in a Kolkata auditorium shared some 11 hours before the news of his death.

Also Read | Celebs, politicians react to singer KK’s death: Sad day for music lovers

“Singer Anupam Roy called me up and said he is hearing something bad from the hospital. Then I contacted the hospital. They said he was brought dead. Then I rushed to the hospital,” Minister Arup Biswas said, according to Hindustan Times.

The singer was known for songs like ‘Pal’ and ‘Yaaron,’ which became a massive hit in the late 1990s.

Celebrities and his fans took to Twitter to express their shock over the his sudden death.

“Extremely sad and devastated. Another shocking loss for all of us. Can’t believe our KK sir is no more… what is even happening. I can’t take it anymore,” Armaan Malik wrote.

Also Read | KK’s last Instagram post from Kolkata gig shows his stage excitement | See pics

Cricketer Virendar Sehwag wrote: “Tragic to hear about the passing away of KK after falling ill while performing in Kolkata. Another reminder of how fragile life is. Condolences to his family and friends. Om Shanti.”

Some of his popular tracks include ‘Tadap Tadap’ (Hum Dil De Chuke Sanam, 1999), ‘Dus Bahane’ (Dus, 2005), and ‘Tune Maari Entriyaan’ (Gunday, 2014).