ET has learned that Cruz died on Saturday from heart disease.
David Cruz, who dated Jennifer Lopez for nearly a decade, has died. He was 51.
The New York City Office of Chief Medical Examiner confirmed to ET that Cruz died on Saturday at the Mount Sinai West Hospital in Manhattan, New York. They also confirmed that the cause of death was heart disease.
Lopez and Cruz began dating when she was 15 years old, and the two were high school sweethearts. They were together for almost 10 years before calling it quits in the mid-'90s -- just as Lopez's career began to rise.
The two attended a few Hollywood events together. They were last publicly photographed on the red carpet together at the Money Train premiere in Culver City, California, in November 1995.
Lopez is currently engaged to former MLB star Alex Rodriguez. She shares two kids, 12-year-old twins Emme and Maximilian, with ex-husband Marc Anthony.