Gabriel Olsen via Getty Images Juan Gabriel at one of his final concerts at The Forum on Aug. 26.

Mexican singer and icon Alberto Aguilera Valadez, best known as Juan Gabriel, died from a heart attack on Sunday around 11:30 a.m. in Santa Monica, California, Univision reports. He was 66.

The singer-songwriter, affectionately called JuanGa and El Divo de Juárez, was on tour at the time of his death. The 22-city “MeXXIco es Todo” tour kicked off in San Diego on Aug. 19. He was expected to perform in El Paso, Texas, on Sunday night.

Juan Gabriel was born in Parácuaro, Michoacán, on Jan. 7, 1950. He was one of Mexico’s most renowned vocalists with hits including “Querida,” “Se Me Olvidó Otra Vez,” “Amor Eterno” and “El Noa Noa.”

The singer kept his private life firmly under wraps during his career, famously refusing to confirm or deny any questions about his sexuality. He never married but had four children with his best friend, Laura Salas.

In a statement to the press, his family called him a giant in the music industry as well as a beloved father and grandfather.

“My father’s untimely passing is a tragic loss for all of us, his family, colleagues, and fans alike, “Juan Gabriel’s son Ivan Aguilera stated. “We give heartfelt thanks for the outpouring of condolences we have received from around the world including from President Enrique Pena Nieto. We know that our father will miss entertaining his countless fans, who brought him tremendous joy in life.”