Cause of Haywood's death unknown Associated Press DALLAS -- Just days before Dallas Cowboys running back Ennis Haywood died of a brief illness, he had impressed teammates with his performance at workouts. An autopsy was to be scheduled Monday for Haywood, who was placed on life support at Medical Center of Arlington before his death on Sunday. "The cause of death at this time is unknown,'' hospital spokeswoman Diane Stout told The Associated Press. Stout said she doesn't know why Haywood, 23, was being treated. But she said an autopsy would determine the cause of death. Haywood's sister-in-law, Angela Jernigan,...