Mexican superstar Juan Gabriel, the bigger than life performer who at 66 years old revamped his career in spectacular fashion, has died unexpectedly, Billboard reported. 

Juan Gabriel was in the midst of the U.S. leg of his  MeXXico Es Todos tour,  a 22-city arena trek that had him playing on 360 stages to accommodate sold out crowds. 

On Sunday morning (Aug. 28), sources close to him said he was in Los Angeles, where had played the Forum Friday night.  As he readied to go to the airport to fly to El Paso, the next stop on his tour, he suffered a massive heart attack. An official statement from the family is expected to come.

At the time of his death, Juan Gabriel, already one of Latin music’s biggest superstars, was arguably at the apex of his career, despite his age. 

He ranked at No. 18 on Billboard’s 2015 Money Makers list (just below Ed Sheeran and just above Florida Georgia Line), largely thanks to $11.6 million in touring revenue in 2015. He scored the year’s highest-grossing Latin tour and had the top-selling Latin album, Los Duo, which has moved 131,000 units, according to Nielsen Music.

The week before his death, his latest album, Vestido de Etiqueta: Por Eduardo Magallanes, debuted at No. 1 on Billboard’s Top Latin Albums chart.  In the fall, Telemundo will begin airing a TV series based on his life. 

While Juan Gabriel was a prodigal performer who reveled in singing three, four even five-hour concerts, his biggest claim to fame were his songs -- romantic, colloquial, emotional compositions that sometimes rambled but managed to strike a universal chord with lyrics that could apply to many people and many situations.  

He was versatile  and traversed pop and mariachi with ease, his songs perfectly suited for both formats. Up to the day of his death, Juan Gabriel would tour with both his pop band and his longtime mariachi. 

Juan Gabriel leaves behind a desolate legion of fans spread around the world, and Sunday afternoon he was the top-trending Twitter topic worldwide, outpacing even the VMAs. The thousands of Twitter messages from fans illustrated his pan-generational appeal.