Juan Gabriel, one of Mexico’s leading singers and songwriters, died Sunday. He was 66.

TMZ reports that Gabriel died in Santa Monica, Calif., of a suspected heart attack. His body is currently with the Los Angeles County medical examiner, and no foul play is expected.

Gabriel had just embarked on the biggest tour of his career. He was in the middle of the U.S. leg of his 22-city MeXXico Es Todos tour, playing to sold-out crowds on 360 stages. He had most recently performed in Los Angeles at the Forum on Friday night.

The Mexican icon was one of the country’s top earners in music. Over his career, Gabriel has sold more than 30 million records. Last year, he earned $11.6 million in touring revenue. His 13th album, “Los Duo,” was the top-selling Latin album of the year in 2015.

Gabriel was born Alberto Aguilera Valadez in the small town of Paracuaro, Michoacan, in 1950, the youngest of ten siblings. He got his start in music at a young age, being sent to boarding school at the age of five where a teacher, Juan Contreras, encouraged his singing and writing talents.

He ran away from boarding school at the age of 15. He would go on to sign a record contract with RCA Records in 1971, when he was 21, and officially changed his name.

He became known to fans for his songs of love and heartbreak. On stage, he performed his mariachi tunes flamboyantly, jumping about in bright colors and sequined jackets.

Over the course of his career, he received many honors, including a Lifetime Achievement Award from La Opinion Tributo Nacional, a People’s Choice Latin Music Award and a star on the Hollywood Walk of Fame.