Traffic Police Inspector Jorge Hernandez Pena told reporters that Feliciano may have lost control on a curve and crossed lanes before hitting a power line pole. He was not wearing a seat belt and his head struck the windshield. He died at the scene, police said.
The singer's son, José Enrique Feliciano, said at the scene that his father, who had recently been treated for cancer, had a health condition that may have impaired mobility in one of his arms. He also raised the possibility that the singer fell asleep at the wheel.
"Papi is forever," Feliciano said. "Thank God we have his music to remember him by."
Feliciano was a member of the Fania All Stars and had established his own production company in the 1980s. He also became a prominent anti-drug spokesman after becoming addicted to heroin while living in New York and returning to Puerto Rico for rehabilitation.
Feliciano is survived by his wife, Coco Feliciano, and four sons. Funeral arrangements were not immediately known.