Emilio Navaira, the American-born, Grammy-winning singer known as the King of Tejano Music, died Monday of a heart attack, according to multiple news sources. He was 53. Navaira, who charted nearly a dozen singles on the Billboard Hot Latin Tracks chart, over the course of his career, was found unconscious at his house, police in New Braunfels, Texas, said. His greatest country hit was 1995’s “It’s Not the End of the World," which rose as high as No. 27. His song “Por Siempre Unidos” made the top 10 the following year, peaking at No. 7 on Latin Pop Airplay.